Provided by: libspreadsheet-writeexcel-perl_2.40-1_all bug

NAME

       Spreadsheet::WriteExcel - Write to a cross-platform Excel binary file.

VERSION

       This document refers to version 2.40 of Spreadsheet::WriteExcel, released November 6,
       2013.

SYNOPSIS

       To write a string, a formatted string, a number and a formula to the first worksheet in an
       Excel workbook called perl.xls:

           use Spreadsheet::WriteExcel;

           # Create a new Excel workbook
           my $workbook = Spreadsheet::WriteExcel->new('perl.xls');

           # Add a worksheet
           $worksheet = $workbook->add_worksheet();

           #  Add and define a format
           $format = $workbook->add_format(); # Add a format
           $format->set_bold();
           $format->set_color('red');
           $format->set_align('center');

           # Write a formatted and unformatted string, row and column notation.
           $col = $row = 0;
           $worksheet->write($row, $col, 'Hi Excel!', $format);
           $worksheet->write(1,    $col, 'Hi Excel!');

           # Write a number and a formula using A1 notation
           $worksheet->write('A3', 1.2345);
           $worksheet->write('A4', '=SIN(PI()/4)');

DESCRIPTION

       The Spreadsheet::WriteExcel Perl module can be used to create a cross-platform Excel
       binary file. Multiple worksheets can be added to a workbook and formatting can be applied
       to cells. Text, numbers, formulas, hyperlinks, images and charts can be written to the
       cells.

       The file produced by this module is compatible with Excel 97, 2000, 2002, 2003 and 2007.

       The module will work on the majority of Windows, UNIX and Mac platforms. Generated files
       are also compatible with the Linux/UNIX spreadsheet applications Gnumeric and
       OpenOffice.org.

       This module cannot be used to write to an existing Excel file (See "MODIFYING AND
       REWRITING EXCEL FILES").

       Note: This module is in maintenance only mode and in future will only be updated with bug
       fixes. The newer, more feature rich and API compatible Excel::Writer::XLSX module is
       recommended instead. See, "Migrating to Excel::Writer::XLSX".

QUICK START

       Spreadsheet::WriteExcel tries to provide an interface to as many of Excel's features as
       possible. As a result there is a lot of documentation to accompany the interface and it
       can be difficult at first glance to see what it important and what is not. So for those of
       you who prefer to assemble Ikea furniture first and then read the instructions, here are
       three easy steps:

       1. Create a new Excel workbook (i.e. file) using "new()".

       2. Add a worksheet to the new workbook using "add_worksheet()".

       3. Write to the worksheet using "write()".

       Like this:

           use Spreadsheet::WriteExcel;                             # Step 0

           my $workbook = Spreadsheet::WriteExcel->new('perl.xls'); # Step 1
           $worksheet   = $workbook->add_worksheet();               # Step 2
           $worksheet->write('A1', 'Hi Excel!');                    # Step 3

       This will create an Excel file called "perl.xls" with a single worksheet and the text 'Hi
       Excel!' in the relevant cell. And that's it. Okay, so there is actually a zeroth step as
       well, but "use module" goes without saying. There are also more than 80 examples that come
       with the distribution and which you can use to get you started. See "EXAMPLES".

       Those of you who read the instructions first and assemble the furniture afterwards will
       know how to proceed. ;-)

WORKBOOK METHODS

       The Spreadsheet::WriteExcel module provides an object oriented interface to a new Excel
       workbook. The following methods are available through a new workbook.

           new()
           add_worksheet()
           add_format()
           add_chart()
           add_chart_ext()
           close()
           compatibility_mode()
           set_properties()
           define_name()
           set_tempdir()
           set_custom_color()
           sheets()
           set_1904()
           set_codepage()

       If you are unfamiliar with object oriented interfaces or the way that they are implemented
       in Perl have a look at "perlobj" and "perltoot" in the main Perl documentation.

   new()
       A new Excel workbook is created using the "new()" constructor which accepts either a
       filename or a filehandle as a parameter. The following example creates a new Excel file
       based on a filename:

           my $workbook  = Spreadsheet::WriteExcel->new('filename.xls');
           my $worksheet = $workbook->add_worksheet();
           $worksheet->write(0, 0, 'Hi Excel!');

       Here are some other examples of using "new()" with filenames:

           my $workbook1 = Spreadsheet::WriteExcel->new($filename);
           my $workbook2 = Spreadsheet::WriteExcel->new('/tmp/filename.xls');
           my $workbook3 = Spreadsheet::WriteExcel->new("c:\\tmp\\filename.xls");
           my $workbook4 = Spreadsheet::WriteExcel->new('c:\tmp\filename.xls');

       The last two examples demonstrates how to create a file on DOS or Windows where it is
       necessary to either escape the directory separator "\" or to use single quotes to ensure
       that it isn't interpolated. For more information  see "perlfaq5: Why can't I use
       "C:\temp\foo" in DOS paths?".

       The "new()" constructor returns a Spreadsheet::WriteExcel object that you can use to add
       worksheets and store data. It should be noted that although "my" is not specifically
       required it defines the scope of the new workbook variable and, in the majority of cases,
       ensures that the workbook is closed properly without explicitly calling the "close()"
       method.

       If the file cannot be created, due to file permissions or some other reason,  "new" will
       return "undef". Therefore, it is good practice to check the return value of "new" before
       proceeding. As usual the Perl variable $! will be set if there is a file creation error.
       You will also see one of the warning messages detailed in "DIAGNOSTICS":

           my $workbook  = Spreadsheet::WriteExcel->new('protected.xls');
           die "Problems creating new Excel file: $!" unless defined $workbook;

       You can also pass a valid filehandle to the "new()" constructor. For example in a CGI
       program you could do something like this:

           binmode(STDOUT);
           my $workbook  = Spreadsheet::WriteExcel->new(\*STDOUT);

       The requirement for "binmode()" is explained below.

       See also, the "cgi.pl" program in the "examples" directory of the distro.

       However, this special case will not work in "mod_perl" programs where you will have to do
       something like the following:

           # mod_perl 1
           ...
           tie *XLS, 'Apache';
           binmode(XLS);
           my $workbook  = Spreadsheet::WriteExcel->new(\*XLS);
           ...

           # mod_perl 2
           ...
           tie *XLS => $r;  # Tie to the Apache::RequestRec object
           binmode(*XLS);
           my $workbook  = Spreadsheet::WriteExcel->new(\*XLS);
           ...

       See also, the "mod_perl1.pl" and "mod_perl2.pl" programs in the "examples" directory of
       the distro.

       Filehandles can also be useful if you want to stream an Excel file over a socket or if you
       want to store an Excel file in a scalar.

       For example here is a way to write an Excel file to a scalar with "perl 5.8":

           #!/usr/bin/perl -w

           use strict;
           use Spreadsheet::WriteExcel;

           # Requires perl 5.8 or later
           open my $fh, '>', \my $str or die "Failed to open filehandle: $!";

           my $workbook  = Spreadsheet::WriteExcel->new($fh);
           my $worksheet = $workbook->add_worksheet();

           $worksheet->write(0, 0,  'Hi Excel!');

           $workbook->close();

           # The Excel file in now in $str. Remember to binmode() the output
           # filehandle before printing it.
           binmode STDOUT;
           print $str;

       See also the "write_to_scalar.pl" and "filehandle.pl" programs in the "examples" directory
       of the distro.

       Note about the requirement for "binmode()". An Excel file is comprised of binary data.
       Therefore, if you are using a filehandle you should ensure that you "binmode()" it prior
       to passing it to "new()".You should do this regardless of whether you are on a Windows
       platform or not. This applies especially to users of perl 5.8 on systems where "UTF-8" is
       likely to be in operation such as RedHat Linux 9. If your program, either intentionally or
       not, writes "UTF-8" data to a filehandle that is passed to "new()" it will corrupt the
       Excel file that is created.

       You don't have to worry about "binmode()" if you are using filenames instead of
       filehandles. Spreadsheet::WriteExcel performs the "binmode()" internally when it converts
       the filename to a filehandle. For more information about "binmode()" see "perlfunc" and
       "perlopentut" in the main Perl documentation.

   add_worksheet($sheetname, $utf_16_be)
       At least one worksheet should be added to a new workbook. A worksheet is used to write
       data into cells:

           $worksheet1 = $workbook->add_worksheet();           # Sheet1
           $worksheet2 = $workbook->add_worksheet('Foglio2');  # Foglio2
           $worksheet3 = $workbook->add_worksheet('Data');     # Data
           $worksheet4 = $workbook->add_worksheet();           # Sheet4

       If $sheetname is not specified the default Excel convention will be followed, i.e. Sheet1,
       Sheet2, etc. The $utf_16_be parameter is optional, see below.

       The worksheet name must be a valid Excel worksheet name, i.e. it cannot contain any of the
       following characters, "[ ] : * ? / \" and it must be less than 32 characters. In addition,
       you cannot use the same, case insensitive, $sheetname for more than one worksheet.

       On systems with "perl 5.8" and later the "add_worksheet()" method will also handle strings
       in "UTF-8" format.

           $worksheet = $workbook->add_worksheet("\x{263a}"); # Smiley

       On earlier Perl systems your can specify "UTF-16BE" worksheet names using an additional
       optional parameter:

           my $name = pack 'n', 0x263a;
           $worksheet = $workbook->add_worksheet($name, 1);   # Smiley

   add_format(%properties)
       The "add_format()" method can be used to create new Format objects which are used to apply
       formatting to a cell. You can either define the properties at creation time via a hash of
       property values or later via method calls.

           $format1 = $workbook->add_format(%props); # Set properties at creation
           $format2 = $workbook->add_format();       # Set properties later

       See the "CELL FORMATTING" section for more details about Format properties and how to set
       them.

   add_chart(%properties)
       This method is use to create a new chart either as a standalone worksheet (the default) or
       as an embeddable object that can be inserted into a worksheet via the "insert_chart()"
       Worksheet method.

           my $chart = $workbook->add_chart( type => 'column' );

       The properties that can be set are:

           type     (required)
           name     (optional)
           embedded (optional)

       ·   "type"

           This is a required parameter. It defines the type of chart that will be created.

               my $chart = $workbook->add_chart( type => 'line' );

           The available types are:

               area
               bar
               column
               line
               pie
               scatter
               stock

       ·   "name"

           Set the name for the chart sheet. The name property is optional and if it isn't
           supplied will default to "Chart1 .. n". The name must be a valid Excel worksheet name.
           See "add_worksheet()" for more details on valid sheet names. The "name" property can
           be omitted for embedded charts.

               my $chart = $workbook->add_chart( type => 'line', name => 'Results Chart' );

       ·   "embedded"

           Specifies that the Chart object will be inserted in a worksheet via the
           "insert_chart()" Worksheet method. It is an error to try insert a Chart that doesn't
           have this flag set.

               my $chart = $workbook->add_chart( type => 'line', embedded => 1 );

               # Configure the chart.
               ...

               # Insert the chart into the a worksheet.
               $worksheet->insert_chart( 'E2', $chart );

       See Spreadsheet::WriteExcel::Chart for details on how to configure the chart object once
       it is created. See also the "chart_*.pl" programs in the examples directory of the distro.

   add_chart_ext($chart_data, $chartname)
       This method is use to include externally generated charts in a Spreadsheet::WriteExcel
       file.

           my $chart = $workbook->add_chart_ext('chart01.bin', 'Chart1');

       This feature is semi-deprecated in favour of the "native" charts created using
       "add_chart()". Read "external_charts.txt" (or ".pod") in the external_charts directory of
       the distro for a full explanation.

   close()
       In general your Excel file will be closed automatically when your program ends or when the
       Workbook object goes out of scope, however the "close()" method can be used to explicitly
       close an Excel file.

           $workbook->close();

       An explicit "close()" is required if the file must be closed prior to performing some
       external action on it such as copying it, reading its size or attaching it to an email.

       In addition, "close()" may be required to prevent perl's garbage collector from disposing
       of the Workbook, Worksheet and Format objects in the wrong order. Situations where this
       can occur are:

       ·   If "my()" was not used to declare the scope of a workbook variable created using
           "new()".

       ·   If the "new()", "add_worksheet()" or "add_format()" methods are called in subroutines.

       The reason for this is that Spreadsheet::WriteExcel relies on Perl's "DESTROY" mechanism
       to trigger destructor methods in a specific sequence. This may not happen in cases where
       the Workbook, Worksheet and Format variables are not lexically scoped or where they have
       different lexical scopes.

       In general, if you create a file with a size of 0 bytes or you fail to create a file you
       need to call "close()".

       The return value of "close()" is the same as that returned by perl when it closes the file
       created by "new()". This allows you to handle error conditions in the usual way:

           $workbook->close() or die "Error closing file: $!";

   compatibility_mode()
       This method is used to improve compatibility with third party applications that read Excel
       files.

           $workbook->compatibility_mode();

       An Excel file is comprised of binary records that describe properties of a spreadsheet.
       Excel is reasonably liberal about this and, outside of a core subset, it doesn't require
       every possible record to be present when it reads a file. This is also true of Gnumeric
       and OpenOffice.Org Calc.

       Spreadsheet::WriteExcel takes advantage of this fact to omit some records in order to
       minimise the amount of data stored in memory and to simplify and speed up the writing of
       files. However, some third party applications that read Excel files often expect certain
       records to be present. In "compatibility mode" Spreadsheet::WriteExcel writes these
       records and tries to be as close to an Excel generated file as possible.

       Applications that require "compatibility_mode()" are Apache POI, Apple Numbers, and
       Quickoffice on Nokia, Palm and other devices. You should also use "compatibility_mode()"
       if your Excel file will be used as an external data source by another Excel file.

       If you encounter other situations that require "compatibility_mode()", please let me know.

       It should be noted that "compatibility_mode()" requires additional data to be stored in
       memory and additional processing. This incurs a memory and speed penalty and may not be
       suitable for very large files (>20MB).

       You must call "compatibility_mode()" before calling "add_worksheet()".

   set_properties()
       The "set_properties" method can be used to set the document properties of the Excel file
       created by "Spreadsheet::WriteExcel". These properties are visible when you use the
       "File->Properties" menu option in Excel and are also available to external applications
       that read or index windows files.

       The properties should be passed as a hash of values as follows:

           $workbook->set_properties(
               title    => 'This is an example spreadsheet',
               author   => 'John McNamara',
               comments => 'Created with Perl and Spreadsheet::WriteExcel',
           );

       The properties that can be set are:

           title
           subject
           author
           manager
           company
           category
           keywords
           comments

       User defined properties are not supported due to effort required.

       In perl 5.8+ you can also pass UTF-8 strings as properties. See "UNICODE IN EXCEL".

           my $smiley = chr 0x263A;

           $workbook->set_properties(
               subject => "Happy now? $smiley",
           );

       With older versions of perl you can use a module to convert a non-ASCII string to a binary
       representation of UTF-8 and then pass an additional "utf8" flag to "set_properties()":

           my $smiley = pack 'H*', 'E298BA';

           $workbook->set_properties(
               subject => "Happy now? $smiley",
               utf8    => 1,
           );

       Usually Spreadsheet::WriteExcel allows you to use UTF-16 with pre 5.8 versions of perl.
       However, document properties don't support UTF-16 for these type of strings.

       In order to promote the usefulness of Perl and the Spreadsheet::WriteExcel module consider
       adding a comment such as the following when using document properties:

           $workbook->set_properties(
               ...,
               comments => 'Created with Perl and Spreadsheet::WriteExcel',
               ...,
           );

       This feature requires that the "OLE::Storage_Lite" module is installed (which is usually
       the case for a standard Spreadsheet::WriteExcel installation). However, this also means
       that the resulting OLE document may possibly be buggy for files less than 7MB since it
       hasn't been as rigorously tested in that domain. As a result of this "set_properties" is
       currently incompatible with Gnumeric for files less than 7MB. This is being investigated.
       If you encounter any problems with this features let me know.

       For convenience it is possible to pass either a hash or hash ref of arguments to this
       method.

       See also the "properties.pl" program in the examples directory of the distro.

   define_name()
       This method is used to defined a name that can be used to represent a value, a single cell
       or a range of cells in a workbook.

           $workbook->define_name('Exchange_rate', '=0.96');
           $workbook->define_name('Sales',         '=Sheet1!$G$1:$H$10');
           $workbook->define_name('Sheet2!Sales',  '=Sheet2!$G$1:$G$10');

       See the defined_name.pl program in the examples dir of the distro.

       Note: This currently a beta feature. More documentation and examples will be added.

   set_tempdir()
       For speed and efficiency "Spreadsheet::WriteExcel" stores worksheet data in temporary
       files prior to assembling the final workbook.

       If Spreadsheet::WriteExcel is unable to create these temporary files it will store the
       required data in memory. This can be slow for large files.

       The problem occurs mainly with IIS on Windows although it could feasibly occur on Unix
       systems as well. The problem generally occurs because the default temp file directory is
       defined as "C:/" or some other directory that IIS doesn't provide write access to.

       To check if this might be a problem on a particular system you can run a simple test
       program with "-w" or "use warnings". This will generate a warning if the module cannot
       create the required temporary files:

           #!/usr/bin/perl -w

           use Spreadsheet::WriteExcel;

           my $workbook  = Spreadsheet::WriteExcel->new('test.xls');
           my $worksheet = $workbook->add_worksheet();

       To avoid this problem the "set_tempdir()" method can be used to specify a directory that
       is accessible for the creation of temporary files.

       The "File::Temp" module is used to create the temporary files. File::Temp uses
       "File::Spec" to determine an appropriate location for these files such as "/tmp" or
       "c:\windows\temp". You can find out which directory is used on your system as follows:

           perl -MFile::Spec -le "print File::Spec->tmpdir"

       Even if the default temporary file directory is accessible you may wish to specify an
       alternative location for security or maintenance reasons:

           $workbook->set_tempdir('/tmp/writeexcel');
           $workbook->set_tempdir('c:\windows\temp\writeexcel');

       The directory for the temporary file must exist, "set_tempdir()" will not create a new
       directory.

       One disadvantage of using the "set_tempdir()" method is that on some Windows systems it
       will limit you to approximately 800 concurrent tempfiles. This means that a single program
       running on one of these systems will be limited to creating a total of 800 workbook and
       worksheet objects. You can run multiple, non-concurrent programs to work around this if
       necessary.

   set_custom_color($index, $red, $green, $blue)
       The "set_custom_color()" method can be used to override one of the built-in palette values
       with a more suitable colour.

       The value for $index should be in the range 8..63, see "COLOURS IN EXCEL".

       The default named colours use the following indices:

            8   =>   black
            9   =>   white
           10   =>   red
           11   =>   lime
           12   =>   blue
           13   =>   yellow
           14   =>   magenta
           15   =>   cyan
           16   =>   brown
           17   =>   green
           18   =>   navy
           20   =>   purple
           22   =>   silver
           23   =>   gray
           33   =>   pink
           53   =>   orange

       A new colour is set using its RGB (red green blue) components. The $red, $green and $blue
       values must be in the range 0..255. You can determine the required values in Excel using
       the "Tools->Options->Colors->Modify" dialog.

       The "set_custom_color()" workbook method can also be used with a HTML style "#rrggbb" hex
       value:

           $workbook->set_custom_color(40, 255,  102,  0   ); # Orange
           $workbook->set_custom_color(40, 0xFF, 0x66, 0x00); # Same thing
           $workbook->set_custom_color(40, '#FF6600'       ); # Same thing

           my $font = $workbook->add_format(color => 40); # Use the modified colour

       The return value from "set_custom_color()" is the index of the colour that was changed:

           my $ferrari = $workbook->set_custom_color(40, 216, 12, 12);

           my $format  = $workbook->add_format(
                                               bg_color => $ferrari,
                                               pattern  => 1,
                                               border   => 1
                                             );

   sheets(0, 1, ...)
       The "sheets()" method returns a list, or a sliced list, of the worksheets in a workbook.

       If no arguments are passed the method returns a list of all the worksheets in the
       workbook. This is useful if you want to repeat an operation on each worksheet:

           foreach $worksheet ($workbook->sheets()) {
              print $worksheet->get_name();
           }

       You can also specify a slice list to return one or more worksheet objects:

           $worksheet = $workbook->sheets(0);
           $worksheet->write('A1', 'Hello');

       Or since return value from "sheets()" is a reference to a worksheet object you can write
       the above example as:

           $workbook->sheets(0)->write('A1', 'Hello');

       The following example returns the first and last worksheet in a workbook:

           foreach $worksheet ($workbook->sheets(0, -1)) {
              # Do something
           }

       Array slices are explained in the perldata manpage.

   set_1904()
       Excel stores dates as real numbers where the integer part stores the number of days since
       the epoch and the fractional part stores the percentage of the day. The epoch can be
       either 1900 or 1904. Excel for Windows uses 1900 and Excel for Macintosh uses 1904.
       However, Excel on either platform will convert automatically between one system and the
       other.

       Spreadsheet::WriteExcel stores dates in the 1900 format by default. If you wish to change
       this you can call the "set_1904()" workbook method. You can query the current value by
       calling the "get_1904()" workbook method. This returns 0 for 1900 and 1 for 1904.

       See also "DATES AND TIME IN EXCEL" for more information about working with Excel's date
       system.

       In general you probably won't need to use "set_1904()".

   set_codepage($codepage)
       The default code page or character set used by Spreadsheet::WriteExcel is ANSI. This is
       also the default used by Excel for Windows. Occasionally however it may be necessary to
       change the code page via the "set_codepage()" method.

       Changing the code page may be required if your are using Spreadsheet::WriteExcel on the
       Macintosh and you are using characters outside the ASCII 128 character set:

           $workbook->set_codepage(1); # ANSI, MS Windows
           $workbook->set_codepage(2); # Apple Macintosh

       The "set_codepage()" method is rarely required.

WORKSHEET METHODS

       A new worksheet is created by calling the "add_worksheet()" method from a workbook object:

           $worksheet1 = $workbook->add_worksheet();
           $worksheet2 = $workbook->add_worksheet();

       The following methods are available through a new worksheet:

           write()
           write_number()
           write_string()
           write_utf16be_string()
           write_utf16le_string()
           keep_leading_zeros()
           write_blank()
           write_row()
           write_col()
           write_date_time()
           write_url()
           write_url_range()
           write_formula()
           store_formula()
           repeat_formula()
           write_comment()
           show_comments()
           add_write_handler()
           insert_image()
           insert_chart()
           data_validation()
           get_name()
           activate()
           select()
           hide()
           set_first_sheet()
           protect()
           set_selection()
           set_row()
           set_column()
           outline_settings()
           freeze_panes()
           split_panes()
           merge_range()
           set_zoom()
           right_to_left()
           hide_zero()
           set_tab_color()
           autofilter()

   Cell notation
       Spreadsheet::WriteExcel supports two forms of notation to designate the position of cells:
       Row-column notation and A1 notation.

       Row-column notation uses a zero based index for both row and column while A1 notation uses
       the standard Excel alphanumeric sequence of column letter and 1-based row. For example:

           (0, 0)      # The top left cell in row-column notation.
           ('A1')      # The top left cell in A1 notation.

           (1999, 29)  # Row-column notation.
           ('AD2000')  # The same cell in A1 notation.

       Row-column notation is useful if you are referring to cells programmatically:

           for my $i (0 .. 9) {
               $worksheet->write($i, 0, 'Hello'); # Cells A1 to A10
           }

       A1 notation is useful for setting up a worksheet manually and for working with formulas:

           $worksheet->write('H1', 200);
           $worksheet->write('H2', '=H1+1');

       In formulas and applicable methods you can also use the "A:A" column notation:

           $worksheet->write('A1', '=SUM(B:B)');

       The "Spreadsheet::WriteExcel::Utility" module that is included in the distro contains
       helper functions for dealing with A1 notation, for example:

           use Spreadsheet::WriteExcel::Utility;

           ($row, $col)    = xl_cell_to_rowcol('C2');  # (1, 2)
           $str            = xl_rowcol_to_cell(1, 2);  # C2

       For simplicity, the parameter lists for the worksheet method calls in the following
       sections are given in terms of row-column notation. In all cases it is also possible to
       use A1 notation.

       Note: in Excel it is also possible to use a R1C1 notation. This is not supported by
       Spreadsheet::WriteExcel.

   write($row, $column, $token, $format)
       Excel makes a distinction between data types such as strings, numbers, blanks, formulas
       and hyperlinks. To simplify the process of writing data the "write()" method acts as a
       general alias for several more specific methods:

           write_string()
           write_number()
           write_blank()
           write_formula()
           write_url()
           write_row()
           write_col()

       The general rule is that if the data looks like a something then a something is written.
       Here are some examples in both row-column and A1 notation:

                                                             # Same as:
           $worksheet->write(0, 0, 'Hello'                ); # write_string()
           $worksheet->write(1, 0, 'One'                  ); # write_string()
           $worksheet->write(2, 0,  2                     ); # write_number()
           $worksheet->write(3, 0,  3.00001               ); # write_number()
           $worksheet->write(4, 0,  ""                    ); # write_blank()
           $worksheet->write(5, 0,  ''                    ); # write_blank()
           $worksheet->write(6, 0,  undef                 ); # write_blank()
           $worksheet->write(7, 0                         ); # write_blank()
           $worksheet->write(8, 0,  'http://www.perl.com/'); # write_url()
           $worksheet->write('A9',  'ftp://ftp.cpan.org/' ); # write_url()
           $worksheet->write('A10', 'internal:Sheet1!A1'  ); # write_url()
           $worksheet->write('A11', 'external:c:\foo.xls' ); # write_url()
           $worksheet->write('A12', '=A3 + 3*A4'          ); # write_formula()
           $worksheet->write('A13', '=SIN(PI()/4)'        ); # write_formula()
           $worksheet->write('A14', \@array               ); # write_row()
           $worksheet->write('A15', [\@array]             ); # write_col()

           # And if the keep_leading_zeros property is set:
           $worksheet->write('A16', '2'                   ); # write_number()
           $worksheet->write('A17', '02'                  ); # write_string()
           $worksheet->write('A18', '00002'               ); # write_string()

       The "looks like" rule is defined by regular expressions:

       "write_number()" if $token is a number based on the following regex: "$token =~
       /^([+-]?)(?=\d|\.\d)\d*(\.\d*)?([Ee]([+-]?\d+))?$/".

       "write_string()" if "keep_leading_zeros()" is set and $token is an integer with leading
       zeros based on the following regex: "$token =~ /^0\d+$/".

       "write_blank()" if $token is undef or a blank string: "undef", "" or ''.

       "write_url()" if $token is a http, https, ftp or mailto URL based on the following
       regexes: "$token =~ m|^[fh]tt?ps?://|" or  "$token =~ m|^mailto:|".

       "write_url()" if $token is an internal or external sheet reference based on the following
       regex: "$token =~ m[^(in|ex)ternal:]".

       "write_formula()" if the first character of $token is "=".

       "write_row()" if $token is an array ref.

       "write_col()" if $token is an array ref of array refs.

       "write_string()" if none of the previous conditions apply.

       The $format parameter is optional. It should be a valid Format object, see "CELL
       FORMATTING":

           my $format = $workbook->add_format();
           $format->set_bold();
           $format->set_color('red');
           $format->set_align('center');

           $worksheet->write(4, 0, 'Hello', $format); # Formatted string

       The write() method will ignore empty strings or "undef" tokens unless a format is also
       supplied. As such you needn't worry about special handling for empty or "undef" values in
       your data. See also the "write_blank()" method.

       One problem with the "write()" method is that occasionally data looks like a number but
       you don't want it treated as a number. For example, zip codes or ID numbers often start
       with a leading zero. If you write this data as a number then the leading zero(s) will be
       stripped. You can change this default behaviour by using the "keep_leading_zeros()"
       method. While this property is in place any integers with leading zeros will be treated as
       strings and the zeros will be preserved. See the "keep_leading_zeros()" section for a full
       discussion of this issue.

       You can also add your own data handlers to the "write()" method using
       "add_write_handler()".

       On systems with "perl 5.8" and later the "write()" method will also handle Unicode strings
       in "UTF-8" format.

       The "write" methods return:

           0 for success.
          -1 for insufficient number of arguments.
          -2 for row or column out of bounds.
          -3 for string too long.

   write_number($row, $column, $number, $format)
       Write an integer or a float to the cell specified by $row and $column:

           $worksheet->write_number(0, 0,  123456);
           $worksheet->write_number('A2',  2.3451);

       See the note about "Cell notation". The $format parameter is optional.

       In general it is sufficient to use the "write()" method.

   write_string($row, $column, $string, $format)
       Write a string to the cell specified by $row and $column:

           $worksheet->write_string(0, 0, 'Your text here' );
           $worksheet->write_string('A2', 'or here' );

       The maximum string size is 32767 characters. However the maximum string segment that Excel
       can display in a cell is 1000. All 32767 characters can be displayed in the formula bar.

       The $format parameter is optional.

       On systems with "perl 5.8" and later the "write()" method will also handle strings in
       "UTF-8" format. With older perls you can also write Unicode in "UTF16" format via the
       "write_utf16be_string()" method. See also the "unicode_*.pl" programs in the examples
       directory of the distro.

       In general it is sufficient to use the "write()" method. However, you may sometimes wish
       to use the "write_string()" method to write data that looks like a number but that you
       don't want treated as a number. For example, zip codes or phone numbers:

           # Write as a plain string
           $worksheet->write_string('A1', '01209');

       However, if the user edits this string Excel may convert it back to a number. To get
       around this you can use the Excel text format "@":

           # Format as a string. Doesn't change to a number when edited
           my $format1 = $workbook->add_format(num_format => '@');
           $worksheet->write_string('A2', '01209', $format1);

       See also the note about "Cell notation".

   write_utf16be_string($row, $column, $string, $format)
       This method is used to write "UTF-16BE" strings to a cell in Excel. It is functionally the
       same as the "write_string()" method except that the string should be in "UTF-16BE" Unicode
       format. It is generally easier, when using Spreadsheet::WriteExcel, to write unicode
       strings in "UTF-8" format, see "UNICODE IN EXCEL". The "write_utf16be_string()" method is
       mainly of use in versions of perl prior to 5.8.

       The following is a simple example showing how to write some Unicode strings in "UTF-16BE"
       format:

           #!/usr/bin/perl -w

           use strict;
           use Spreadsheet::WriteExcel;
           use Unicode::Map();

           my $workbook  = Spreadsheet::WriteExcel->new('utf_16_be.xls');
           my $worksheet = $workbook->add_worksheet();

           # Increase the column width for clarity
           $worksheet->set_column('A:A', 25);

           # Write a Unicode character
           #
           my $smiley = pack 'n', 0x263a;

           # Increase the font size for legibility.
           my $big_font = $workbook->add_format(size => 72);

           $worksheet->write_utf16be_string('A3', $smiley, $big_font);

           # Write a phrase in Cyrillic using a hex-encoded string
           #
           my $str = pack 'H*', '042d0442043e0020044404400430043704300020043d' .
                                '043000200440044304410441043a043e043c0021';

           $worksheet->write_utf16be_string('A5', $str);

           # Map a string to UTF-16BE using an external module.
           #
           my $map   = Unicode::Map->new('ISO-8859-1');
           my $utf16 = $map->to_unicode('Hello world!');

           $worksheet->write_utf16be_string('A7', $utf16);

       You can convert ASCII encodings to the required "UTF-16BE" format using one of the many
       Unicode modules on CPAN. For example "Unicode::Map" and "Unicode::String":
       <http://search.cpan.org/author/MSCHWARTZ/Unicode-Map/Map.pm> and
       <http://search.cpan.org/author/GAAS/Unicode-String/String.pm>.

       For a full list of the Perl Unicode modules see:
       <http://search.cpan.org/search?query=unicode&mode=all>.

       "UTF-16BE" is the format most often returned by "Perl" modules that generate "UTF-16". To
       write "UTF-16" strings in little-endian format use the "write_utf16be_string_le()" method
       below.

       The "write_utf16be_string()" method was previously called "write_unicode()". That, overly
       general, name is still supported but deprecated.

       See also the "unicode_*.pl" programs in the examples directory of the distro.

   write_utf16le_string($row, $column, $string, $format)
       This method is the same as "write_utf16be()" except that the string should be 16-bit
       characters in little-endian format. This is generally referred to as "UTF-16LE". See
       "UNICODE IN EXCEL".

       "UTF-16" data can be changed from little-endian to big-endian format (and vice-versa) as
       follows:

           $utf16be = pack 'n*', unpack 'v*', $utf16le;

   keep_leading_zeros()
       This method changes the default handling of integers with leading zeros when using the
       "write()" method.

       The "write()" method uses regular expressions to determine what type of data to write to
       an Excel worksheet. If the data looks like a number it writes a number using
       "write_number()". One problem with this approach is that occasionally data looks like a
       number but you don't want it treated as a number.

       Zip codes and ID numbers, for example, often start with a leading zero. If you write this
       data as a number then the leading zero(s) will be stripped. This is the also the default
       behaviour when you enter data manually in Excel.

       To get around this you can use one of three options. Write a formatted number, write the
       number as a string or use the "keep_leading_zeros()" method to change the default
       behaviour of "write()":

           # Implicitly write a number, the leading zero is removed: 1209
           $worksheet->write('A1', '01209');

           # Write a zero padded number using a format: 01209
           my $format1 = $workbook->add_format(num_format => '00000');
           $worksheet->write('A2', '01209', $format1);

           # Write explicitly as a string: 01209
           $worksheet->write_string('A3', '01209');

           # Write implicitly as a string: 01209
           $worksheet->keep_leading_zeros();
           $worksheet->write('A4', '01209');

       The above code would generate a worksheet that looked like the following:

            -----------------------------------------------------------
           |   |     A     |     B     |     C     |     D     | ...
            -----------------------------------------------------------
           | 1 |      1209 |           |           |           | ...
           | 2 |     01209 |           |           |           | ...
           | 3 | 01209     |           |           |           | ...
           | 4 | 01209     |           |           |           | ...

       The examples are on different sides of the cells due to the fact that Excel displays
       strings with a left justification and numbers with a right justification by default. You
       can change this by using a format to justify the data, see "CELL FORMATTING".

       It should be noted that if the user edits the data in examples "A3" and "A4" the strings
       will revert back to numbers. Again this is Excel's default behaviour. To avoid this you
       can use the text format "@":

           # Format as a string (01209)
           my $format2 = $workbook->add_format(num_format => '@');
           $worksheet->write_string('A5', '01209', $format2);

       The "keep_leading_zeros()" property is off by default. The "keep_leading_zeros()" method
       takes 0 or 1 as an argument. It defaults to 1 if an argument isn't specified:

           $worksheet->keep_leading_zeros();  # Set on
           $worksheet->keep_leading_zeros(1); # Set on
           $worksheet->keep_leading_zeros(0); # Set off

       See also the "add_write_handler()" method.

   write_blank($row, $column, $format)
       Write a blank cell specified by $row and $column:

           $worksheet->write_blank(0, 0, $format);

       This method is used to add formatting to a cell which doesn't contain a string or number
       value.

       Excel differentiates between an "Empty" cell and a "Blank" cell. An "Empty" cell is a cell
       which doesn't contain data whilst a "Blank" cell is a cell which doesn't contain data but
       does contain formatting. Excel stores "Blank" cells but ignores "Empty" cells.

       As such, if you write an empty cell without formatting it is ignored:

           $worksheet->write('A1',  undef, $format); # write_blank()
           $worksheet->write('A2',  undef         ); # Ignored

       This seemingly uninteresting fact means that you can write arrays of data without special
       treatment for undef or empty string values.

       See the note about "Cell notation".

   write_row($row, $column, $array_ref, $format)
       The "write_row()" method can be used to write a 1D or 2D array of data in one go. This is
       useful for converting the results of a database query into an Excel worksheet. You must
       pass a reference to the array of data rather than the array itself. The "write()" method
       is then called for each element of the data. For example:

           @array      = ('awk', 'gawk', 'mawk');
           $array_ref  = \@array;

           $worksheet->write_row(0, 0, $array_ref);

           # The above example is equivalent to:
           $worksheet->write(0, 0, $array[0]);
           $worksheet->write(0, 1, $array[1]);
           $worksheet->write(0, 2, $array[2]);

       Note: For convenience the "write()" method behaves in the same way as "write_row()" if it
       is passed an array reference. Therefore the following two method calls are equivalent:

           $worksheet->write_row('A1', $array_ref); # Write a row of data
           $worksheet->write(    'A1', $array_ref); # Same thing

       As with all of the write methods the $format parameter is optional. If a format is
       specified it is applied to all the elements of the data array.

       Array references within the data will be treated as columns. This allows you to write 2D
       arrays of data in one go. For example:

           @eec =  (
                       ['maggie', 'milly', 'molly', 'may'  ],
                       [13,       14,      15,      16     ],
                       ['shell',  'star',  'crab',  'stone']
                   );

           $worksheet->write_row('A1', \@eec);

       Would produce a worksheet as follows:

            -----------------------------------------------------------
           |   |    A    |    B    |    C    |    D    |    E    | ...
            -----------------------------------------------------------
           | 1 | maggie  | 13      | shell   | ...     |  ...    | ...
           | 2 | milly   | 14      | star    | ...     |  ...    | ...
           | 3 | molly   | 15      | crab    | ...     |  ...    | ...
           | 4 | may     | 16      | stone   | ...     |  ...    | ...
           | 5 | ...     | ...     | ...     | ...     |  ...    | ...
           | 6 | ...     | ...     | ...     | ...     |  ...    | ...

       To write the data in a row-column order refer to the "write_col()" method below.

       Any "undef" values in the data will be ignored unless a format is applied to the data, in
       which case a formatted blank cell will be written. In either case the appropriate row or
       column value will still be incremented.

       To find out more about array references refer to "perlref" and "perlreftut" in the main
       Perl documentation. To find out more about 2D arrays or "lists of lists" refer to
       "perllol".

       The "write_row()" method returns the first error encountered when writing the elements of
       the data or zero if no errors were encountered. See the return values described for the
       "write()" method above.

       See also the "write_arrays.pl" program in the "examples" directory of the distro.

       The "write_row()" method allows the following idiomatic conversion of a text file to an
       Excel file:

           #!/usr/bin/perl -w

           use strict;
           use Spreadsheet::WriteExcel;

           my $workbook  = Spreadsheet::WriteExcel->new('file.xls');
           my $worksheet = $workbook->add_worksheet();

           open INPUT, 'file.txt' or die "Couldn't open file: $!";

           $worksheet->write($.-1, 0, [split]) while <INPUT>;

   write_col($row, $column, $array_ref, $format)
       The "write_col()" method can be used to write a 1D or 2D array of data in one go. This is
       useful for converting the results of a database query into an Excel worksheet. You must
       pass a reference to the array of data rather than the array itself. The "write()" method
       is then called for each element of the data. For example:

           @array      = ('awk', 'gawk', 'mawk');
           $array_ref  = \@array;

           $worksheet->write_col(0, 0, $array_ref);

           # The above example is equivalent to:
           $worksheet->write(0, 0, $array[0]);
           $worksheet->write(1, 0, $array[1]);
           $worksheet->write(2, 0, $array[2]);

       As with all of the write methods the $format parameter is optional. If a format is
       specified it is applied to all the elements of the data array.

       Array references within the data will be treated as rows. This allows you to write 2D
       arrays of data in one go. For example:

           @eec =  (
                       ['maggie', 'milly', 'molly', 'may'  ],
                       [13,       14,      15,      16     ],
                       ['shell',  'star',  'crab',  'stone']
                   );

           $worksheet->write_col('A1', \@eec);

       Would produce a worksheet as follows:

            -----------------------------------------------------------
           |   |    A    |    B    |    C    |    D    |    E    | ...
            -----------------------------------------------------------
           | 1 | maggie  | milly   | molly   | may     |  ...    | ...
           | 2 | 13      | 14      | 15      | 16      |  ...    | ...
           | 3 | shell   | star    | crab    | stone   |  ...    | ...
           | 4 | ...     | ...     | ...     | ...     |  ...    | ...
           | 5 | ...     | ...     | ...     | ...     |  ...    | ...
           | 6 | ...     | ...     | ...     | ...     |  ...    | ...

       To write the data in a column-row order refer to the "write_row()" method above.

       Any "undef" values in the data will be ignored unless a format is applied to the data, in
       which case a formatted blank cell will be written. In either case the appropriate row or
       column value will still be incremented.

       As noted above the "write()" method can be used as a synonym for "write_row()" and
       "write_row()" handles nested array refs as columns. Therefore, the following two method
       calls are equivalent although the more explicit call to "write_col()" would be preferable
       for maintainability:

           $worksheet->write_col('A1', $array_ref    ); # Write a column of data
           $worksheet->write(    'A1', [ $array_ref ]); # Same thing

       To find out more about array references refer to "perlref" and "perlreftut" in the main
       Perl documentation. To find out more about 2D arrays or "lists of lists" refer to
       "perllol".

       The "write_col()" method returns the first error encountered when writing the elements of
       the data or zero if no errors were encountered. See the return values described for the
       "write()" method above.

       See also the "write_arrays.pl" program in the "examples" directory of the distro.

   write_date_time($row, $col, $date_string, $format)
       The "write_date_time()" method can be used to write a date or time to the cell specified
       by $row and $column:

           $worksheet->write_date_time('A1', '2004-05-13T23:20', $date_format);

       The $date_string should be in the following format:

           yyyy-mm-ddThh:mm:ss.sss

       This conforms to an ISO8601 date but it should be noted that the full range of ISO8601
       formats are not supported.

       The following variations on the $date_string parameter are permitted:

           yyyy-mm-ddThh:mm:ss.sss         # Standard format
           yyyy-mm-ddT                     # No time
                     Thh:mm:ss.sss         # No date
           yyyy-mm-ddThh:mm:ss.sssZ        # Additional Z (but not time zones)
           yyyy-mm-ddThh:mm:ss             # No fractional seconds
           yyyy-mm-ddThh:mm                # No seconds

       Note that the "T" is required in all cases.

       A date should always have a $format, otherwise it will appear as a number, see "DATES AND
       TIME IN EXCEL" and "CELL FORMATTING". Here is a typical example:

           my $date_format = $workbook->add_format(num_format => 'mm/dd/yy');
           $worksheet->write_date_time('A1', '2004-05-13T23:20', $date_format);

       Valid dates should be in the range 1900-01-01 to 9999-12-31, for the 1900 epoch and
       1904-01-01 to 9999-12-31, for the 1904 epoch. As with Excel, dates outside these ranges
       will be written as a string.

       See also the date_time.pl program in the "examples" directory of the distro.

   write_url($row, $col, $url, $label, $format)
       Write a hyperlink to a URL in the cell specified by $row and $column. The hyperlink is
       comprised of two elements: the visible label and the invisible link. The visible label is
       the same as the link unless an alternative label is specified. The parameters $label and
       the $format are optional and their position is interchangeable.

       The label is written using the "write()" method. Therefore it is possible to write
       strings, numbers or formulas as labels.

       There are four web style URI's supported: "http://", "https://", "ftp://" and  "mailto:":

           $worksheet->write_url(0, 0,  'ftp://www.perl.org/'                  );
           $worksheet->write_url(1, 0,  'http://www.perl.com/', 'Perl home'    );
           $worksheet->write_url('A3',  'http://www.perl.com/', $format        );
           $worksheet->write_url('A4',  'http://www.perl.com/', 'Perl', $format);
           $worksheet->write_url('A5',  'mailto:jmcnamara@cpan.org'            );

       There are two local URIs supported: "internal:" and "external:". These are used for
       hyperlinks to internal worksheet references or external workbook and worksheet references:

           $worksheet->write_url('A6',  'internal:Sheet2!A1'                   );
           $worksheet->write_url('A7',  'internal:Sheet2!A1',   $format        );
           $worksheet->write_url('A8',  'internal:Sheet2!A1:B2'                );
           $worksheet->write_url('A9',  q{internal:'Sales Data'!A1}            );
           $worksheet->write_url('A10', 'external:c:\temp\foo.xls'             );
           $worksheet->write_url('A11', 'external:c:\temp\foo.xls#Sheet2!A1'   );
           $worksheet->write_url('A12', 'external:..\..\..\foo.xls'            );
           $worksheet->write_url('A13', 'external:..\..\..\foo.xls#Sheet2!A1'  );
           $worksheet->write_url('A13', 'external:\\\\NETWORK\share\foo.xls'   );

       All of the these URI types are recognised by the "write()" method, see above.

       Worksheet references are typically of the form "Sheet1!A1". You can also refer to a
       worksheet range using the standard Excel notation: "Sheet1!A1:B2".

       In external links the workbook and worksheet name must be separated by the "#" character:
       "external:Workbook.xls#Sheet1!A1'".

       You can also link to a named range in the target worksheet. For example say you have a
       named range called "my_name" in the workbook "c:\temp\foo.xls" you could link to it as
       follows:

           $worksheet->write_url('A14', 'external:c:\temp\foo.xls#my_name');

       Note, you cannot currently create named ranges with "Spreadsheet::WriteExcel".

       Excel requires that worksheet names containing spaces or non alphanumeric characters are
       single quoted as follows "'Sales Data'!A1". If you need to do this in a single quoted
       string then you can either escape the single quotes "\'" or use the quote operator "q{}"
       as described in "perlop" in the main Perl documentation.

       Links to network files are also supported. MS/Novell Network files normally begin with two
       back slashes as follows "\\NETWORK\etc". In order to generate this in a single or double
       quoted string you will have to escape the backslashes,  '\\\\NETWORK\etc'.

       If you are using double quote strings then you should be careful to escape anything that
       looks like a metacharacter. For more information  see "perlfaq5: Why can't I use
       "C:\temp\foo" in DOS paths?".

       Finally, you can avoid most of these quoting problems by using forward slashes. These are
       translated internally to backslashes:

           $worksheet->write_url('A14', "external:c:/temp/foo.xls"             );
           $worksheet->write_url('A15', 'external://NETWORK/share/foo.xls'     );

       See also, the note about "Cell notation".

   write_url_range($row1, $col1, $row2, $col2, $url, $string, $format)
       This method is essentially the same as the "write_url()" method described above. The main
       difference is that you can specify a link for a range of cells:

           $worksheet->write_url(0, 0, 0, 3, 'ftp://www.perl.org/'              );
           $worksheet->write_url(1, 0, 0, 3, 'http://www.perl.com/', 'Perl home');
           $worksheet->write_url('A3:D3',    'internal:Sheet2!A1'               );
           $worksheet->write_url('A4:D4',    'external:c:\temp\foo.xls'         );

       This method is generally only required when used in conjunction with merged cells. See the
       "merge_range()" method and the "merge" property of a Format object, "CELL FORMATTING".

       There is no way to force this behaviour through the "write()" method.

       The parameters $string and the $format are optional and their position is interchangeable.
       However, they are applied only to the first cell in the range.

       See also, the note about "Cell notation".

   write_formula($row, $column, $formula, $format, $value)
       Write a formula or function to the cell specified by $row and $column:

           $worksheet->write_formula(0, 0, '=$B$3 + B4'  );
           $worksheet->write_formula(1, 0, '=SIN(PI()/4)');
           $worksheet->write_formula(2, 0, '=SUM(B1:B5)' );
           $worksheet->write_formula('A4', '=IF(A3>1,"Yes", "No")'   );
           $worksheet->write_formula('A5', '=AVERAGE(1, 2, 3, 4)'    );
           $worksheet->write_formula('A6', '=DATEVALUE("1-Jan-2001")');

       See the note about "Cell notation". For more information about writing Excel formulas see
       "FORMULAS AND FUNCTIONS IN EXCEL"

       See also the section "Improving performance when working with formulas" and the
       "store_formula()" and "repeat_formula()" methods.

       If required, it is also possible to specify the calculated value of the formula. This is
       occasionally necessary when working with non-Excel applications that don't calculate the
       value of the formula. The calculated $value is added at the end of the argument list:

           $worksheet->write('A1', '=2+2', $format, 4);

       However, this probably isn't something that will ever need to do. If you do use this
       feature then do so with care.

   store_formula($formula)
       The "store_formula()" method is used in conjunction with "repeat_formula()" to speed up
       the generation of repeated formulas. See "Improving performance when working with
       formulas" in "FORMULAS AND FUNCTIONS IN EXCEL".

       The "store_formula()" method pre-parses a textual representation of a formula and stores
       it for use at a later stage by the "repeat_formula()" method.

       "store_formula()" carries the same speed penalty as "write_formula()". However, in
       practice it will be used less frequently.

       The return value of this method is a scalar that can be thought of as a reference to a
       formula.

           my $sin = $worksheet->store_formula('=SIN(A1)');
           my $cos = $worksheet->store_formula('=COS(A1)');

           $worksheet->repeat_formula('B1', $sin, $format, 'A1', 'A2');
           $worksheet->repeat_formula('C1', $cos, $format, 'A1', 'A2');

       Although "store_formula()" is a worksheet method the return value can be used in any
       worksheet:

           my $now = $worksheet->store_formula('=NOW()');

           $worksheet1->repeat_formula('B1', $now);
           $worksheet2->repeat_formula('B1', $now);
           $worksheet3->repeat_formula('B1', $now);

   repeat_formula($row, $col, $formula, $format, ($pattern => $replace, ...))
       The "repeat_formula()" method is used in conjunction with "store_formula()" to speed up
       the generation of repeated formulas.  See "Improving performance when working with
       formulas" in "FORMULAS AND FUNCTIONS IN EXCEL".

       In many respects "repeat_formula()" behaves like "write_formula()" except that it is
       significantly faster.

       The "repeat_formula()" method creates a new formula based on the pre-parsed tokens
       returned by "store_formula()". The new formula is generated by substituting $pattern,
       $replace pairs in the stored formula:

           my $formula = $worksheet->store_formula('=A1 * 3 + 50');

           for my $row (0..99) {
               $worksheet->repeat_formula($row, 1, $formula, $format, 'A1', 'A'.($row +1));
           }

       It should be noted that "repeat_formula()" doesn't modify the tokens. In the above example
       the substitution is always made against the original token, "A1", which doesn't change.

       As usual, you can use "undef" if you don't wish to specify a $format:

           $worksheet->repeat_formula('B2', $formula, $format, 'A1', 'A2');
           $worksheet->repeat_formula('B3', $formula, undef,   'A1', 'A3');

       The substitutions are made from left to right and you can use as many $pattern, $replace
       pairs as you need. However, each substitution is made only once:

           my $formula = $worksheet->store_formula('=A1 + A1');

           # Gives '=B1 + A1'
           $worksheet->repeat_formula('B1', $formula, undef, 'A1', 'B1');

           # Gives '=B1 + B1'
           $worksheet->repeat_formula('B2', $formula, undef, ('A1', 'B1') x 2);

       Since the $pattern is interpolated each time that it is used it is worth using the "qr"
       operator to quote the pattern. The "qr" operator is explained in the "perlop" man page.

           $worksheet->repeat_formula('B1', $formula, $format, qr/A1/, 'A2');

       Care should be taken with the values that are substituted. The formula returned by
       "repeat_formula()" contains several other tokens in addition to those in the formula and
       these might also match the  pattern that you are trying to replace. In particular you
       should avoid substituting a single 0, 1, 2 or 3.

       You should also be careful to avoid false matches. For example the following snippet is
       meant to change the stored formula in steps from "=A1 + SIN(A1)" to "=A10 + SIN(A10)".

           my $formula = $worksheet->store_formula('=A1 + SIN(A1)');

           for my $row (1 .. 10) {
               $worksheet->repeat_formula($row -1, 1, $formula, undef,
                                           qw/A1/, 'A' . $row,   #! Bad.
                                           qw/A1/, 'A' . $row    #! Bad.
                                         );
           }

       However it contains a bug. In the last iteration of the loop when $row is 10 the following
       substitutions will occur:

           s/A1/A10/;    changes    =A1 + SIN(A1)     to    =A10 + SIN(A1)
           s/A1/A10/;    changes    =A10 + SIN(A1)    to    =A100 + SIN(A1) # !!

       The solution in this case is to use a more explicit match such as "qw/^A1$/":

               $worksheet->repeat_formula($row -1, 1, $formula, undef,
                                           qw/^A1$/, 'A' . $row,
                                           qw/^A1$/, 'A' . $row
                                         );

       Another similar problem occurs due to the fact that substitutions are made in order. For
       example the following snippet is meant to change the stored formula from "=A10 + A11"  to
       "=A11 + A12":

           my $formula = $worksheet->store_formula('=A10 + A11');

           $worksheet->repeat_formula('A1', $formula, undef,
                                       qw/A10/, 'A11',   #! Bad.
                                       qw/A11/, 'A12'    #! Bad.
                                     );

       However, the actual substitution yields "=A12 + A11":

           s/A10/A11/;    changes    =A10 + A11    to    =A11 + A11
           s/A11/A12/;    changes    =A11 + A11    to    =A12 + A11 # !!

       The solution here would be to reverse the order of the substitutions or to start with a
       stored formula that won't yield a false match such as "=X10 + Y11":

           my $formula = $worksheet->store_formula('=X10 + Y11');

           $worksheet->repeat_formula('A1', $formula, undef,
                                       qw/X10/, 'A11',
                                       qw/Y11/, 'A12'
                                     );

       If you think that you have a problem related to a false match you can check the tokens
       that you are substituting against as follows.

           my $formula = $worksheet->store_formula('=A1*5+4');
           print "@$formula\n";

       See also the "repeat.pl" program in the "examples" directory of the distro.

   write_comment($row, $column, $string, ...)
       The "write_comment()" method is used to add a comment to a cell. A cell comment is
       indicated in Excel by a small red triangle in the upper right-hand corner of the cell.
       Moving the cursor over the red triangle will reveal the comment.

       The following example shows how to add a comment to a cell:

           $worksheet->write        (2, 2, 'Hello');
           $worksheet->write_comment(2, 2, 'This is a comment.');

       As usual you can replace the $row and $column parameters with an "A1" cell reference. See
       the note about "Cell notation".

           $worksheet->write        ('C3', 'Hello');
           $worksheet->write_comment('C3', 'This is a comment.');

       On systems with "perl 5.8" and later the "write_comment()" method will also handle strings
       in "UTF-8" format.

           $worksheet->write_comment('C3', "\x{263a}");       # Smiley
           $worksheet->write_comment('C4', 'Comment ca va?');

       In addition to the basic 3 argument form of "write_comment()" you can pass in several
       optional key/value pairs to control the format of the comment. For example:

           $worksheet->write_comment('C3', 'Hello', visible => 1, author => 'Perl');

       Most of these options are quite specific and in general the default comment behaviour will
       be all that you need. However, should you need greater control over the format of the cell
       comment the following options are available:

           encoding
           author
           author_encoding
           visible
           x_scale
           width
           y_scale
           height
           color
           start_cell
           start_row
           start_col
           x_offset
           y_offset

       Option: encoding
           This option is used to indicate that the comment string is encoded as "UTF-16BE".

               my $comment = pack 'n', 0x263a; # UTF-16BE Smiley symbol

               $worksheet->write_comment('C3', $comment, encoding => 1);

           If you wish to use Unicode characters in the comment string then the preferred method
           is to use perl 5.8 and "UTF-8" strings, see "UNICODE IN EXCEL".

       Option: author
           This option is used to indicate who the author of the comment is. Excel displays the
           author of the comment in the status bar at the bottom of the worksheet. This is
           usually of interest in corporate environments where several people might review and
           provide comments to a workbook.

               $worksheet->write_comment('C3', 'Atonement', author => 'Ian McEwan');

       Option: author_encoding
           This option is used to indicate that the author string is encoded as "UTF-16BE".

       Option: visible
           This option is used to make a cell comment visible when the worksheet is opened. The
           default behaviour in Excel is that comments are initially hidden. However, it is also
           possible in Excel to make individual or all comments visible. In
           Spreadsheet::WriteExcel individual comments can be made visible as follows:

               $worksheet->write_comment('C3', 'Hello', visible => 1);

           It is possible to make all comments in a worksheet visible using the "show_comments()"
           worksheet method (see below). Alternatively, if all of the cell comments have been
           made visible you can hide individual comments:

               $worksheet->write_comment('C3', 'Hello', visible => 0);

       Option: x_scale
           This option is used to set the width of the cell comment box as a factor of the
           default width.

               $worksheet->write_comment('C3', 'Hello', x_scale => 2);
               $worksheet->write_comment('C4', 'Hello', x_scale => 4.2);

       Option: width
           This option is used to set the width of the cell comment box explicitly in pixels.

               $worksheet->write_comment('C3', 'Hello', width => 200);

       Option: y_scale
           This option is used to set the height of the cell comment box as a factor of the
           default height.

               $worksheet->write_comment('C3', 'Hello', y_scale => 2);
               $worksheet->write_comment('C4', 'Hello', y_scale => 4.2);

       Option: height
           This option is used to set the height of the cell comment box explicitly in pixels.

               $worksheet->write_comment('C3', 'Hello', height => 200);

       Option: color
           This option is used to set the background colour of cell comment box. You can use one
           of the named colours recognised by Spreadsheet::WriteExcel or a colour index. See
           "COLOURS IN EXCEL".

               $worksheet->write_comment('C3', 'Hello', color => 'green');
               $worksheet->write_comment('C4', 'Hello', color => 0x35);    # Orange

       Option: start_cell
           This option is used to set the cell in which the comment will appear. By default Excel
           displays comments one cell to the right and one cell above the cell to which the
           comment relates. However, you can change this behaviour if you wish. In the following
           example the comment which would appear by default in cell "D2" is moved to "E2".

               $worksheet->write_comment('C3', 'Hello', start_cell => 'E2');

       Option: start_row
           This option is used to set the row in which the comment will appear. See the
           "start_cell" option above. The row is zero indexed.

               $worksheet->write_comment('C3', 'Hello', start_row => 0);

       Option: start_col
           This option is used to set the column in which the comment will appear. See the
           "start_cell" option above. The column is zero indexed.

               $worksheet->write_comment('C3', 'Hello', start_col => 4);

       Option: x_offset
           This option is used to change the x offset, in pixels, of a comment within a cell:

               $worksheet->write_comment('C3', $comment, x_offset => 30);

       Option: y_offset
           This option is used to change the y offset, in pixels, of a comment within a cell:

               $worksheet->write_comment('C3', $comment, x_offset => 30);

       You can apply as many of these options as you require.

       See also "ROW HEIGHTS AND WORKSHEET OBJECTS".

   show_comments()
       This method is used to make all cell comments visible when a worksheet is opened.

       Individual comments can be made visible using the "visible" parameter of the
       "write_comment" method (see above):

           $worksheet->write_comment('C3', 'Hello', visible => 1);

       If all of the cell comments have been made visible you can hide individual comments as
       follows:

           $worksheet->write_comment('C3', 'Hello', visible => 0);

   add_write_handler($re, $code_ref)
       This method is used to extend the Spreadsheet::WriteExcel write() method to handle user
       defined data.

       If you refer to the section on "write()" above you will see that it acts as an alias for
       several more specific "write_*" methods. However, it doesn't always act in exactly the way
       that you would like it to.

       One solution is to filter the input data yourself and call the appropriate "write_*"
       method. Another approach is to use the "add_write_handler()" method to add your own
       automated behaviour to "write()".

       The "add_write_handler()" method take two arguments, $re, a regular expression to match
       incoming data and $code_ref a callback function to handle the matched data:

           $worksheet->add_write_handler(qr/^\d\d\d\d$/, \&my_write);

       (In the these examples the "qr" operator is used to quote the regular expression strings,
       see perlop for more details).

       The method is used as follows. say you wished to write 7 digit ID numbers as a string so
       that any leading zeros were preserved*, you could do something like the following:

           $worksheet->add_write_handler(qr/^\d{7}$/, \&write_my_id);

           sub write_my_id {
               my $worksheet = shift;
               return $worksheet->write_string(@_);
           }

       * You could also use the "keep_leading_zeros()" method for this.

       Then if you call "write()" with an appropriate string it will be handled automatically:

           # Writes 0000000. It would normally be written as a number; 0.
           $worksheet->write('A1', '0000000');

       The callback function will receive a reference to the calling worksheet and all of the
       other arguments that were passed to "write()". The callback will see an @_ argument list
       that looks like the following:

           $_[0]   A ref to the calling worksheet. *
           $_[1]   Zero based row number.
           $_[2]   Zero based column number.
           $_[3]   A number or string or token.
           $_[4]   A format ref if any.
           $_[5]   Any other arguments.
           ...

           *  It is good style to shift this off the list so the @_ is the same
              as the argument list seen by write().

       Your callback should "return()" the return value of the "write_*" method that was called
       or "undef" to indicate that you rejected the match and want "write()" to continue as
       normal.

       So for example if you wished to apply the previous filter only to ID values that occur in
       the first column you could modify your callback function as follows:

           sub write_my_id {
               my $worksheet = shift;
               my $col       = $_[1];

               if ($col == 0) {
                   return $worksheet->write_string(@_);
               }
               else {
                   # Reject the match and return control to write()
                   return undef;
               }
           }

       Now, you will get different behaviour for the first column and other columns:

           $worksheet->write('A1', '0000000'); # Writes 0000000
           $worksheet->write('B1', '0000000'); # Writes 0

       You may add more than one handler in which case they will be called in the order that they
       were added.

       Note, the "add_write_handler()" method is particularly suited for handling dates.

       See the "write_handler 1-4" programs in the "examples" directory for further examples.

   insert_image($row, $col, $filename, $x, $y, $scale_x, $scale_y)
       This method can be used to insert a image into a worksheet. The image can be in PNG, JPEG
       or BMP format. The $x, $y, $scale_x and $scale_y parameters are optional.

           $worksheet1->insert_image('A1', 'perl.bmp');
           $worksheet2->insert_image('A1', '../images/perl.bmp');
           $worksheet3->insert_image('A1', '.c:\images\perl.bmp');

       The parameters $x and $y can be used to specify an offset from the top left hand corner of
       the cell specified by $row and $col. The offset values are in pixels.

           $worksheet1->insert_image('A1', 'perl.bmp', 32, 10);

       The default width of a cell is 63 pixels. The default height of a cell is 17 pixels. The
       pixels offsets can be calculated using the following relationships:

           Wp = int(12We)   if We <  1
           Wp = int(7We +5) if We >= 1
           Hp = int(4/3He)

           where:
           We is the cell width in Excels units
           Wp is width in pixels
           He is the cell height in Excels units
           Hp is height in pixels

       The offsets can be greater than the width or height of the underlying cell. This can be
       occasionally useful if you wish to align two or more images relative to the same cell.

       The parameters $scale_x and $scale_y can be used to scale the inserted image horizontally
       and vertically:

           # Scale the inserted image: width x 2.0, height x 0.8
           $worksheet->insert_image('A1', 'perl.bmp', 0, 0, 2, 0.8);

       See also the "images.pl" program in the "examples" directory of the distro.

       BMP images must be 24 bit, true colour, bitmaps. In general it is best to avoid BMP images
       since they aren't compressed. The older "insert_bitmap()" method is still supported but
       deprecated.

       See also "ROW HEIGHTS AND WORKSHEET OBJECTS".

   insert_chart($row, $col, $chart, $x, $y, $scale_x, $scale_y)
       This method can be used to insert a Chart object into a worksheet. The Chart must be
       created by the "add_chart()" Workbook method  and it must have the "embedded" option set.

           my $chart = $workbook->add_chart( type => 'line', embedded => 1 );

           # Configure the chart.
           ...

           # Insert the chart into the a worksheet.
           $worksheet->insert_chart('E2', $chart);

       See "add_chart()" for details on how to create the Chart object and
       Spreadsheet::WriteExcel::Chart for details on how to configure it. See also the
       "chart_*.pl" programs in the examples directory of the distro.

       The $x, $y, $scale_x and $scale_y parameters are optional.

       The parameters $x and $y can be used to specify an offset from the top left hand corner of
       the cell specified by $row and $col. The offset values are in pixels. See the
       "insert_image" method above for more information on sizes.

           $worksheet1->insert_chart('E2', $chart, 3, 3);

       The parameters $scale_x and $scale_y can be used to scale the inserted image horizontally
       and vertically:

           # Scale the width by 120% and the height by 150%
           $worksheet->insert_chart('E2', $chart, 0, 0, 1.2, 1.5);

       The easiest way to calculate the required scaling is to create a test chart worksheet with
       Spreadsheet::WriteExcel. Then open the file, select the chart and drag the corner to get
       the required size. While holding down the mouse the scale of the resized chart is shown to
       the left of the formula bar.

       See also "ROW HEIGHTS AND WORKSHEET OBJECTS".

   embed_chart($row, $col, $filename, $x, $y, $scale_x, $scale_y)
       This method can be used to insert a externally generated chart into a worksheet. The chart
       must first be extracted from an existing Excel file. This feature is semi-deprecated in
       favour of the "native" charts created using "add_chart()". Read "external_charts.txt" (or
       ".pod") in the external_charts directory of the distro for a full explanation.

       Here is an example:

           $worksheet->embed_chart('B2', 'sales_chart.bin');

       The $x, $y, $scale_x and $scale_y parameters are optional. See "insert_chart()" above for
       details.

   data_validation()
       The "data_validation()" method is used to construct an Excel data validation or to limit
       the user input to a dropdown list of values.

           $worksheet->data_validation('B3',
               {
                   validate => 'integer',
                   criteria => '>',
                   value    => 100,
               });

           $worksheet->data_validation('B5:B9',
               {
                   validate => 'list',
                   value    => ['open', 'high', 'close'],
               });

       This method contains a lot of parameters and is described in detail in a separate section
       "DATA VALIDATION IN EXCEL".

       See also the "data_validate.pl" program in the examples directory of the distro

   get_name()
       The "get_name()" method is used to retrieve the name of a worksheet. For example:

           foreach my $sheet ($workbook->sheets()) {
               print $sheet->get_name();
           }

       For reasons related to the design of Spreadsheet::WriteExcel and to the internals of Excel
       there is no "set_name()" method. The only way to set the worksheet name is via the
       "add_worksheet()" method.

   activate()
       The "activate()" method is used to specify which worksheet is initially visible in a
       multi-sheet workbook:

           $worksheet1 = $workbook->add_worksheet('To');
           $worksheet2 = $workbook->add_worksheet('the');
           $worksheet3 = $workbook->add_worksheet('wind');

           $worksheet3->activate();

       This is similar to the Excel VBA activate method. More than one worksheet can be selected
       via the "select()" method, see below, however only one worksheet can be active.

       The default active worksheet is the first worksheet.

   select()
       The "select()" method is used to indicate that a worksheet is selected in a multi-sheet
       workbook:

           $worksheet1->activate();
           $worksheet2->select();
           $worksheet3->select();

       A selected worksheet has its tab highlighted. Selecting worksheets is a way of grouping
       them together so that, for example, several worksheets could be printed in one go. A
       worksheet that has been activated via the "activate()" method will also appear as
       selected.

   hide()
       The "hide()" method is used to hide a worksheet:

           $worksheet2->hide();

       You may wish to hide a worksheet in order to avoid confusing a user with intermediate data
       or calculations.

       A hidden worksheet can not be activated or selected so this method is mutually exclusive
       with the "activate()" and "select()" methods. In addition, since the first worksheet will
       default to being the active worksheet, you cannot hide the first worksheet without
       activating another sheet:

           $worksheet2->activate();
           $worksheet1->hide();

   set_first_sheet()
       The "activate()" method determines which worksheet is initially selected. However, if
       there are a large number of worksheets the selected worksheet may not appear on the
       screen. To avoid this you can select which is the leftmost visible worksheet using
       "set_first_sheet()":

           for (1..20) {
               $workbook->add_worksheet;
           }

           $worksheet21 = $workbook->add_worksheet();
           $worksheet22 = $workbook->add_worksheet();

           $worksheet21->set_first_sheet();
           $worksheet22->activate();

       This method is not required very often. The default value is the first worksheet.

   protect($password)
       The "protect()" method is used to protect a worksheet from modification:

           $worksheet->protect();

       It can be turned off in Excel via the "Tools->Protection->Unprotect Sheet" menu command.

       The "protect()" method also has the effect of enabling a cell's "locked" and "hidden"
       properties if they have been set. A "locked" cell cannot be edited. A "hidden" cell will
       display the results of a formula but not the formula itself. In Excel a cell's locked
       property is on by default.

           # Set some format properties
           my $unlocked  = $workbook->add_format(locked => 0);
           my $hidden    = $workbook->add_format(hidden => 1);

           # Enable worksheet protection
           $worksheet->protect();

           # This cell cannot be edited, it is locked by default
           $worksheet->write('A1', '=1+2');

           # This cell can be edited
           $worksheet->write('A2', '=1+2', $unlocked);

           # The formula in this cell isn't visible
           $worksheet->write('A3', '=1+2', $hidden);

       See also the "set_locked" and "set_hidden" format methods in "CELL FORMATTING".

       You can optionally add a password to the worksheet protection:

           $worksheet->protect('drowssap');

       Note, the worksheet level password in Excel provides very weak protection. It does not
       encrypt your data in any way and it is very easy to deactivate. Therefore, do not use the
       above method if you wish to protect sensitive data or calculations. However, before you
       get worried, Excel's own workbook level password protection does provide strong encryption
       in Excel 97+. For technical reasons this will never be supported by
       "Spreadsheet::WriteExcel".

   set_selection($first_row, $first_col, $last_row, $last_col)
       This method can be used to specify which cell or cells are selected in a worksheet. The
       most common requirement is to select a single cell, in which case $last_row and $last_col
       can be omitted. The active cell within a selected range is determined by the order in
       which $first and $last are specified. It is also possible to specify a cell or a range
       using A1 notation. See the note about "Cell notation".

       Examples:

           $worksheet1->set_selection(3, 3);       # 1. Cell D4.
           $worksheet2->set_selection(3, 3, 6, 6); # 2. Cells D4 to G7.
           $worksheet3->set_selection(6, 6, 3, 3); # 3. Cells G7 to D4.
           $worksheet4->set_selection('D4');       # Same as 1.
           $worksheet5->set_selection('D4:G7');    # Same as 2.
           $worksheet6->set_selection('G7:D4');    # Same as 3.

       The default cell selections is (0, 0), 'A1'.

   set_row($row, $height, $format, $hidden, $level, $collapsed)
       This method can be used to change the default properties of a row. All parameters apart
       from $row are optional.

       The most common use for this method is to change the height of a row:

           $worksheet->set_row(0, 20); # Row 1 height set to 20

       If you wish to set the format without changing the height you can pass "undef" as the
       height parameter:

           $worksheet->set_row(0, undef, $format);

       The $format parameter will be applied to any cells in the row that don't  have a format.
       For example

           $worksheet->set_row(0, undef, $format1);    # Set the format for row 1
           $worksheet->write('A1', 'Hello');           # Defaults to $format1
           $worksheet->write('B1', 'Hello', $format2); # Keeps $format2

       If you wish to define a row format in this way you should call the method before any calls
       to "write()". Calling it afterwards will overwrite any format that was previously
       specified.

       The $hidden parameter should be set to 1 if you wish to hide a row. This can be used, for
       example, to hide intermediary steps in a complicated calculation:

           $worksheet->set_row(0, 20,    $format, 1);
           $worksheet->set_row(1, undef, undef,   1);

       The $level parameter is used to set the outline level of the row. Outlines are described
       in "OUTLINES AND GROUPING IN EXCEL". Adjacent rows with the same outline level are grouped
       together into a single outline.

       The following example sets an outline level of 1 for rows 1 and 2 (zero-indexed):

           $worksheet->set_row(1, undef, undef, 0, 1);
           $worksheet->set_row(2, undef, undef, 0, 1);

       The $hidden parameter can also be used to hide collapsed outlined rows when used in
       conjunction with the $level parameter.

           $worksheet->set_row(1, undef, undef, 1, 1);
           $worksheet->set_row(2, undef, undef, 1, 1);

       For collapsed outlines you should also indicate which row has the collapsed "+" symbol
       using the optional $collapsed parameter.

           $worksheet->set_row(3, undef, undef, 0, 0, 1);

       For a more complete example see the "outline.pl" and "outline_collapsed.pl" programs in
       the examples directory of the distro.

       Excel allows up to 7 outline levels. Therefore the $level parameter should be in the range
       "0 <= $level <= 7".

   set_column($first_col, $last_col, $width, $format, $hidden, $level, $collapsed)
       This method can be used to change the default properties of a single column or a range of
       columns. All parameters apart from $first_col and $last_col are optional.

       If "set_column()" is applied to a single column the value of $first_col and $last_col
       should be the same. In the case where $last_col is zero it is set to the same value as
       $first_col.

       It is also possible, and generally clearer, to specify a column range using the form of A1
       notation used for columns. See the note about "Cell notation".

       Examples:

           $worksheet->set_column(0, 0,  20); # Column  A   width set to 20
           $worksheet->set_column(1, 3,  30); # Columns B-D width set to 30
           $worksheet->set_column('E:E', 20); # Column  E   width set to 20
           $worksheet->set_column('F:H', 30); # Columns F-H width set to 30

       The width corresponds to the column width value that is specified in Excel. It is
       approximately equal to the length of a string in the default font of Arial 10.
       Unfortunately, there is no way to specify "AutoFit" for a column in the Excel file format.
       This feature is only available at runtime from within Excel.

       As usual the $format parameter is optional, for additional information, see "CELL
       FORMATTING". If you wish to set the format without changing the width you can pass "undef"
       as the width parameter:

           $worksheet->set_column(0, 0, undef, $format);

       The $format parameter will be applied to any cells in the column that don't  have a
       format. For example

           $worksheet->set_column('A:A', undef, $format1); # Set format for col 1
           $worksheet->write('A1', 'Hello');               # Defaults to $format1
           $worksheet->write('A2', 'Hello', $format2);     # Keeps $format2

       If you wish to define a column format in this way you should call the method before any
       calls to "write()". If you call it afterwards it won't have any effect.

       A default row format takes precedence over a default column format

           $worksheet->set_row(0, undef,        $format1); # Set format for row 1
           $worksheet->set_column('A:A', undef, $format2); # Set format for col 1
           $worksheet->write('A1', 'Hello');               # Defaults to $format1
           $worksheet->write('A2', 'Hello');               # Defaults to $format2

       The $hidden parameter should be set to 1 if you wish to hide a column. This can be used,
       for example, to hide intermediary steps in a complicated calculation:

           $worksheet->set_column('D:D', 20,    $format, 1);
           $worksheet->set_column('E:E', undef, undef,   1);

       The $level parameter is used to set the outline level of the column. Outlines are
       described in "OUTLINES AND GROUPING IN EXCEL". Adjacent columns with the same outline
       level are grouped together into a single outline.

       The following example sets an outline level of 1 for columns B to G:

           $worksheet->set_column('B:G', undef, undef, 0, 1);

       The $hidden parameter can also be used to hide collapsed outlined columns when used in
       conjunction with the $level parameter.

           $worksheet->set_column('B:G', undef, undef, 1, 1);

       For collapsed outlines you should also indicate which row has the collapsed "+" symbol
       using the optional $collapsed parameter.

           $worksheet->set_column('H:H', undef, undef, 0, 0, 1);

       For a more complete example see the "outline.pl" and "outline_collapsed.pl" programs in
       the examples directory of the distro.

       Excel allows up to 7 outline levels. Therefore the $level parameter should be in the range
       "0 <= $level <= 7".

   outline_settings($visible, $symbols_below, $symbols_right, $auto_style)
       The "outline_settings()" method is used to control the appearance of outlines in Excel.
       Outlines are described in "OUTLINES AND GROUPING IN EXCEL".

       The $visible parameter is used to control whether or not outlines are visible. Setting
       this parameter to 0 will cause all outlines on the worksheet to be hidden. They can be
       unhidden in Excel by means of the "Show Outline Symbols" command button. The default
       setting is 1 for visible outlines.

           $worksheet->outline_settings(0);

       The $symbols_below parameter is used to control whether the row outline symbol will appear
       above or below the outline level bar. The default setting is 1 for symbols to appear below
       the outline level bar.

       The "symbols_right" parameter is used to control whether the column outline symbol will
       appear to the left or the right of the outline level bar. The default setting is 1 for
       symbols to appear to the right of the outline level bar.

       The $auto_style parameter is used to control whether the automatic outline generator in
       Excel uses automatic styles when creating an outline. This has no effect on a file
       generated by "Spreadsheet::WriteExcel" but it does have an effect on how the worksheet
       behaves after it is created. The default setting is 0 for "Automatic Styles" to be turned
       off.

       The default settings for all of these parameters correspond to Excel's default parameters.

       The worksheet parameters controlled by "outline_settings()" are rarely used.

   freeze_panes($row, $col, $top_row, $left_col)
       This method can be used to divide a worksheet into horizontal or vertical regions known as
       panes and to also "freeze" these panes so that the splitter bars are not visible. This is
       the same as the "Window->Freeze Panes" menu command in Excel

       The parameters $row and $col are used to specify the location of the split. It should be
       noted that the split is specified at the top or left of a cell and that the method uses
       zero based indexing. Therefore to freeze the first row of a worksheet it is necessary to
       specify the split at row 2 (which is 1 as the zero-based index). This might lead you to
       think that you are using a 1 based index but this is not the case.

       You can set one of the $row and $col parameters as zero if you do not want either a
       vertical or horizontal split.

       Examples:

           $worksheet->freeze_panes(1, 0); # Freeze the first row
           $worksheet->freeze_panes('A2'); # Same using A1 notation
           $worksheet->freeze_panes(0, 1); # Freeze the first column
           $worksheet->freeze_panes('B1'); # Same using A1 notation
           $worksheet->freeze_panes(1, 2); # Freeze first row and first 2 columns
           $worksheet->freeze_panes('C2'); # Same using A1 notation

       The parameters $top_row and $left_col are optional. They are used to specify the top-most
       or left-most visible row or column in the scrolling region of the panes. For example to
       freeze the first row and to have the scrolling region begin at row twenty:

           $worksheet->freeze_panes(1, 0, 20, 0);

       You cannot use A1 notation for the $top_row and $left_col parameters.

       See also the "panes.pl" program in the "examples" directory of the distribution.

   split_panes($y, $x, $top_row, $left_col)
       This method can be used to divide a worksheet into horizontal or vertical regions known as
       panes. This method is different from the "freeze_panes()" method in that the splits
       between the panes will be visible to the user and each pane will have its own scroll bars.

       The parameters $y and $x are used to specify the vertical and horizontal position of the
       split. The units for $y and $x are the same as those used by Excel to specify row height
       and column width. However, the vertical and horizontal units are different from each
       other. Therefore you must specify the $y and $x parameters in terms of the row heights and
       column widths that you have set or the default values which are 12.75 for a row and  8.43
       for a column.

       You can set one of the $y and $x parameters as zero if you do not want either a vertical
       or horizontal split. The parameters $top_row and $left_col are optional. They are used to
       specify the top-most or left-most visible row or column in the bottom-right pane.

       Example:

           $worksheet->split_panes(12.75, 0,    1, 0); # First row
           $worksheet->split_panes(0,     8.43, 0, 1); # First column
           $worksheet->split_panes(12.75, 8.43, 1, 1); # First row and column

       You cannot use A1 notation with this method.

       See also the "freeze_panes()" method and the "panes.pl" program in the "examples"
       directory of the distribution.

       Note: This "split_panes()" method was called "thaw_panes()" in older versions. The older
       name is still available for backwards compatibility.

   merge_range($first_row, $first_col, $last_row, $last_col, $token, $format, $utf_16_be)
       Merging cells can be achieved by setting the "merge" property of a Format object, see
       "CELL FORMATTING". However, this only allows simple Excel5 style horizontal merging which
       Excel refers to as "center across selection".

       The "merge_range()" method allows you to do Excel97+ style formatting where the cells can
       contain other types of alignment in addition to the merging:

           my $format = $workbook->add_format(
                                               border  => 6,
                                               valign  => 'vcenter',
                                               align   => 'center',
                                             );

           $worksheet->merge_range('B3:D4', 'Vertical and horizontal', $format);

       WARNING. The format object that is used with a "merge_range()" method call is marked
       internally as being associated with a merged range. It is a fatal error to use a merged
       format in a non-merged cell. Instead you should use separate formats for merged and non-
       merged cells. This restriction will be removed in a future release.

       The $utf_16_be parameter is optional, see below.

       "merge_range()" writes its $token argument using the worksheet "write()" method. Therefore
       it will handle numbers, strings, formulas or urls as required.

       Setting the "merge" property of the format isn't required when you are using
       "merge_range()". In fact using it will exclude the use of any other horizontal alignment
       option.

       On systems with "perl 5.8" and later the "merge_range()" method will also handle strings
       in "UTF-8" format.

           $worksheet->merge_range('B3:D4', "\x{263a}", $format); # Smiley

       On earlier Perl systems your can specify "UTF-16BE" worksheet names using an additional
       optional parameter:

           my $str = pack 'n', 0x263a;
           $worksheet->merge_range('B3:D4', $str, $format, 1); # Smiley

       The full possibilities of this method are shown in the "merge3.pl" to "merge6.pl" programs
       in the "examples" directory of the distribution.

   set_zoom($scale)
       Set the worksheet zoom factor in the range "10 <= $scale <= 400":

           $worksheet1->set_zoom(50);
           $worksheet2->set_zoom(75);
           $worksheet3->set_zoom(300);
           $worksheet4->set_zoom(400);

       The default zoom factor is 100. You cannot zoom to "Selection" because it is calculated by
       Excel at run-time.

       Note, "set_zoom()" does not affect the scale of the printed page. For that you should use
       "set_print_scale()".

   right_to_left()
       The "right_to_left()" method is used to change the default direction of the worksheet from
       left-to-right, with the A1 cell in the top left, to right-to-left, with the he A1 cell in
       the top right.

           $worksheet->right_to_left();

       This is useful when creating Arabic, Hebrew or other near or far eastern worksheets that
       use right-to-left as the default direction.

   hide_zero()
       The "hide_zero()" method is used to hide any zero values that appear in cells.

           $worksheet->hide_zero();

       In Excel this option is found under Tools->Options->View.

   set_tab_color()
       The "set_tab_color()" method is used to change the colour of the worksheet tab. This
       feature is only available in Excel 2002 and later. You can use one of the standard colour
       names provided by the Format object or a colour index. See "COLOURS IN EXCEL" and the
       "set_custom_color()" method.

           $worksheet1->set_tab_color('red');
           $worksheet2->set_tab_color(0x0C);

       See the "tab_colors.pl" program in the examples directory of the distro.

   autofilter($first_row, $first_col, $last_row, $last_col)
       This method allows an autofilter to be added to a worksheet. An autofilter is a way of
       adding drop down lists to the headers of a 2D range of worksheet data. This in turn allow
       users to filter the data based on simple criteria so that some data is shown and some is
       hidden.

       To add an autofilter to a worksheet:

           $worksheet->autofilter(0, 0, 10, 3);
           $worksheet->autofilter('A1:D11');    # Same as above in A1 notation.

       Filter conditions can be applied using the "filter_column()" method.

       See the "autofilter.pl" program in the examples directory of the distro for a more
       detailed example.

   filter_column($column, $expression)
       The "filter_column" method can be used to filter columns in a autofilter range based on
       simple conditions.

       NOTE: It isn't sufficient to just specify the filter condition. You must also hide any
       rows that don't match the filter condition. Rows are hidden using the "set_row()"
       "visible" parameter. "Spreadsheet::WriteExcel" cannot do this automatically since it isn't
       part of the file format. See the "autofilter.pl" program in the examples directory of the
       distro for an example.

       The conditions for the filter are specified using simple expressions:

           $worksheet->filter_column('A', 'x > 2000');
           $worksheet->filter_column('B', 'x > 2000 and x < 5000');

       The $column parameter can either be a zero indexed column number or a string column name.

       The following operators are available:

           Operator        Synonyms
              ==           =   eq  =~
              !=           <>  ne  !=
              >
              <
              >=
              <=

              and          &&
              or           ||

       The operator synonyms are just syntactic sugar to make you more comfortable using the
       expressions. It is important to remember that the expressions will be interpreted by Excel
       and not by perl.

       An expression can comprise a single statement or two statements separated by the "and" and
       "or" operators. For example:

           'x <  2000'
           'x >  2000'
           'x == 2000'
           'x >  2000 and x <  5000'
           'x == 2000 or  x == 5000'

       Filtering of blank or non-blank data can be achieved by using a value of "Blanks" or
       "NonBlanks" in the expression:

           'x == Blanks'
           'x == NonBlanks'

       Top 10 style filters can be specified using a expression like the following:

           Top|Bottom 1-500 Items|%

       For example:

           'Top    10 Items'
           'Bottom  5 Items'
           'Top    25 %'
           'Bottom 50 %'

       Excel also allows some simple string matching operations:

           'x =~ b*'   # begins with b
           'x !~ b*'   # doesn't begin with b
           'x =~ *b'   # ends with b
           'x !~ *b'   # doesn't end with b
           'x =~ *b*'  # contains b
           'x !~ *b*'  # doesn't contains b

       You can also use "*" to match any character or number and "?" to match any single
       character or number. No other regular expression quantifier is supported by Excel's
       filters. Excel's regular expression characters can be escaped using "~".

       The placeholder variable "x" in the above examples can be replaced by any simple string.
       The actual placeholder name is ignored internally so the following are all equivalent:

           'x     < 2000'
           'col   < 2000'
           'Price < 2000'

       Also, note that a filter condition can only be applied to a column in a range specified by
       the "autofilter()" Worksheet method.

       See the "autofilter.pl" program in the examples directory of the distro for a more
       detailed example.

PAGE SET-UP METHODS

       Page set-up methods affect the way that a worksheet looks when it is printed. They control
       features such as page headers and footers and margins. These methods are really just
       standard worksheet methods. They are documented here in a separate section for the sake of
       clarity.

       The following methods are available for page set-up:

           set_landscape()
           set_portrait()
           set_page_view()
           set_paper()
           center_horizontally()
           center_vertically()
           set_margins()
           set_header()
           set_footer()
           repeat_rows()
           repeat_columns()
           hide_gridlines()
           print_row_col_headers()
           print_area()
           print_across()
           fit_to_pages()
           set_start_page()
           set_print_scale()
           set_h_pagebreaks()
           set_v_pagebreaks()

       A common requirement when working with Spreadsheet::WriteExcel is to apply the same page
       set-up features to all of the worksheets in a workbook. To do this you can use the
       "sheets()" method of the "workbook" class to access the array of worksheets in a workbook:

           foreach $worksheet ($workbook->sheets()) {
              $worksheet->set_landscape();
           }

   set_landscape()
       This method is used to set the orientation of a worksheet's printed page to landscape:

           $worksheet->set_landscape(); # Landscape mode

   set_portrait()
       This method is used to set the orientation of a worksheet's printed page to portrait. The
       default worksheet orientation is portrait, so you won't generally need to call this
       method.

           $worksheet->set_portrait(); # Portrait mode

   set_page_view()
       This method is used to display the worksheet in "Page View" mode. This is currently only
       supported by Mac Excel, where it is the default.

           $worksheet->set_page_view();

   set_paper($index)
       This method is used to set the paper format for the printed output of a worksheet. The
       following paper styles are available:

           Index   Paper format            Paper size
           =====   ============            ==========
             0     Printer default         -
             1     Letter                  8 1/2 x 11 in
             2     Letter Small            8 1/2 x 11 in
             3     Tabloid                 11 x 17 in
             4     Ledger                  17 x 11 in
             5     Legal                   8 1/2 x 14 in
             6     Statement               5 1/2 x 8 1/2 in
             7     Executive               7 1/4 x 10 1/2 in
             8     A3                      297 x 420 mm
             9     A4                      210 x 297 mm
            10     A4 Small                210 x 297 mm
            11     A5                      148 x 210 mm
            12     B4                      250 x 354 mm
            13     B5                      182 x 257 mm
            14     Folio                   8 1/2 x 13 in
            15     Quarto                  215 x 275 mm
            16     -                       10x14 in
            17     -                       11x17 in
            18     Note                    8 1/2 x 11 in
            19     Envelope  9             3 7/8 x 8 7/8
            20     Envelope 10             4 1/8 x 9 1/2
            21     Envelope 11             4 1/2 x 10 3/8
            22     Envelope 12             4 3/4 x 11
            23     Envelope 14             5 x 11 1/2
            24     C size sheet            -
            25     D size sheet            -
            26     E size sheet            -
            27     Envelope DL             110 x 220 mm
            28     Envelope C3             324 x 458 mm
            29     Envelope C4             229 x 324 mm
            30     Envelope C5             162 x 229 mm
            31     Envelope C6             114 x 162 mm
            32     Envelope C65            114 x 229 mm
            33     Envelope B4             250 x 353 mm
            34     Envelope B5             176 x 250 mm
            35     Envelope B6             176 x 125 mm
            36     Envelope                110 x 230 mm
            37     Monarch                 3.875 x 7.5 in
            38     Envelope                3 5/8 x 6 1/2 in
            39     Fanfold                 14 7/8 x 11 in
            40     German Std Fanfold      8 1/2 x 12 in
            41     German Legal Fanfold    8 1/2 x 13 in

       Note, it is likely that not all of these paper types will be available to the end user
       since it will depend on the paper formats that the user's printer supports. Therefore, it
       is best to stick to standard paper types.

           $worksheet->set_paper(1); # US Letter
           $worksheet->set_paper(9); # A4

       If you do not specify a paper type the worksheet will print using the printer's default
       paper.

   center_horizontally()
       Center the worksheet data horizontally between the margins on the printed page:

           $worksheet->center_horizontally();

   center_vertically()
       Center the worksheet data vertically between the margins on the printed page:

           $worksheet->center_vertically();

   set_margins($inches)
       There are several methods available for setting the worksheet margins on the printed page:

           set_margins()        # Set all margins to the same value
           set_margins_LR()     # Set left and right margins to the same value
           set_margins_TB()     # Set top and bottom margins to the same value
           set_margin_left();   # Set left margin
           set_margin_right();  # Set right margin
           set_margin_top();    # Set top margin
           set_margin_bottom(); # Set bottom margin

       All of these methods take a distance in inches as a parameter. Note: 1 inch = 25.4mm. ;-)
       The default left and right margin is 0.75 inch. The default top and bottom margin is 1.00
       inch.

   set_header($string, $margin)
       Headers and footers are generated using a $string which is a combination of plain text and
       control characters. The $margin parameter is optional.

       The available control character are:

           Control             Category            Description
           =======             ========            ===========
           &L                  Justification       Left
           &C                                      Center
           &R                                      Right

           &P                  Information         Page number
           &N                                      Total number of pages
           &D                                      Date
           &T                                      Time
           &F                                      File name
           &A                                      Worksheet name
           &Z                                      Workbook path

           &fontsize           Font                Font size
           &"font,style"                           Font name and style
           &U                                      Single underline
           &E                                      Double underline
           &S                                      Strikethrough
           &X                                      Superscript
           &Y                                      Subscript

           &&                  Miscellaneous       Literal ampersand &

       Text in headers and footers can be justified (aligned) to the left, center and right by
       prefixing the text with the control characters &L, &C and &R.

       For example (with ASCII art representation of the results):

           $worksheet->set_header('&LHello');

            ---------------------------------------------------------------
           |                                                               |
           | Hello                                                         |
           |                                                               |

           $worksheet->set_header('&CHello');

            ---------------------------------------------------------------
           |                                                               |
           |                          Hello                                |
           |                                                               |

           $worksheet->set_header('&RHello');

            ---------------------------------------------------------------
           |                                                               |
           |                                                         Hello |
           |                                                               |

       For simple text, if you do not specify any justification the text will be centred.
       However, you must prefix the text with &C if you specify a font name or any other
       formatting:

           $worksheet->set_header('Hello');

            ---------------------------------------------------------------
           |                                                               |
           |                          Hello                                |
           |                                                               |

       You can have text in each of the justification regions:

           $worksheet->set_header('&LCiao&CBello&RCielo');

            ---------------------------------------------------------------
           |                                                               |
           | Ciao                     Bello                          Cielo |
           |                                                               |

       The information control characters act as variables that Excel will update as the workbook
       or worksheet changes. Times and dates are in the users default format:

           $worksheet->set_header('&CPage &P of &N');

            ---------------------------------------------------------------
           |                                                               |
           |                        Page 1 of 6                            |
           |                                                               |

           $worksheet->set_header('&CUpdated at &T');

            ---------------------------------------------------------------
           |                                                               |
           |                    Updated at 12:30 PM                        |
           |                                                               |

       You can specify the font size of a section of the text by prefixing it with the control
       character &n where "n" is the font size:

           $worksheet1->set_header('&C&30Hello Big'  );
           $worksheet2->set_header('&C&10Hello Small');

       You can specify the font of a section of the text by prefixing it with the control
       sequence "&"font,style"" where "fontname" is a font name such as "Courier New" or "Times
       New Roman" and "style" is one of the standard Windows font descriptions: "Regular",
       "Italic", "Bold" or "Bold Italic":

           $worksheet1->set_header('&C&"Courier New,Italic"Hello');
           $worksheet2->set_header('&C&"Courier New,Bold Italic"Hello');
           $worksheet3->set_header('&C&"Times New Roman,Regular"Hello');

       It is possible to combine all of these features together to create sophisticated headers
       and footers. As an aid to setting up complicated headers and footers you can record a page
       set-up as a macro in Excel and look at the format strings that VBA produces. Remember
       however that VBA uses two double quotes "" to indicate a single double quote. For the last
       example above the equivalent VBA code looks like this:

           .LeftHeader   = ""
           .CenterHeader = "&""Times New Roman,Regular""Hello"
           .RightHeader  = ""

       To include a single literal ampersand "&" in a header or footer you should use a double
       ampersand "&&":

           $worksheet1->set_header('&CCuriouser && Curiouser - Attorneys at Law');

       As stated above the margin parameter is optional. As with the other margins the value
       should be in inches. The default header and footer margin is 0.50 inch. The header and
       footer margin size can be set as follows:

           $worksheet->set_header('&CHello', 0.75);

       The header and footer margins are independent of the top and bottom margins.

       Note, the header or footer string must be less than 255 characters. Strings longer than
       this will not be written and a warning will be generated.

       On systems with "perl 5.8" and later the "set_header()" method can also handle Unicode
       strings in "UTF-8" format.

           $worksheet->set_header("&C\x{263a}")

       See, also the "headers.pl" program in the "examples" directory of the distribution.

   set_footer()
       The syntax of the "set_footer()" method is the same as "set_header()",  see above.

   repeat_rows($first_row, $last_row)
       Set the number of rows to repeat at the top of each printed page.

       For large Excel documents it is often desirable to have the first row or rows of the
       worksheet print out at the top of each page. This can be achieved by using the
       "repeat_rows()" method. The parameters $first_row and $last_row are zero based. The
       $last_row parameter is optional if you only wish to specify one row:

           $worksheet1->repeat_rows(0);    # Repeat the first row
           $worksheet2->repeat_rows(0, 1); # Repeat the first two rows

   repeat_columns($first_col, $last_col)
       Set the columns to repeat at the left hand side of each printed page.

       For large Excel documents it is often desirable to have the first column or columns of the
       worksheet print out at the left hand side of each page. This can be achieved by using the
       "repeat_columns()" method. The parameters $first_column and $last_column are zero based.
       The $last_column parameter is optional if you only wish to specify one column. You can
       also specify the columns using A1 column notation, see the note about "Cell notation".

           $worksheet1->repeat_columns(0);     # Repeat the first column
           $worksheet2->repeat_columns(0, 1);  # Repeat the first two columns
           $worksheet3->repeat_columns('A:A'); # Repeat the first column
           $worksheet4->repeat_columns('A:B'); # Repeat the first two columns

   hide_gridlines($option)
       This method is used to hide the gridlines on the screen and printed page. Gridlines are
       the lines that divide the cells on a worksheet. Screen and printed gridlines are turned on
       by default in an Excel worksheet. If you have defined your own cell borders you may wish
       to hide the default gridlines.

           $worksheet->hide_gridlines();

       The following values of $option are valid:

           0 : Don't hide gridlines
           1 : Hide printed gridlines only
           2 : Hide screen and printed gridlines

       If you don't supply an argument or use "undef" the default option is 1, i.e. only the
       printed gridlines are hidden.

   print_row_col_headers()
       Set the option to print the row and column headers on the printed page.

       An Excel worksheet looks something like the following;

            ------------------------------------------
           |   |   A   |   B   |   C   |   D   |  ...
            ------------------------------------------
           | 1 |       |       |       |       |  ...
           | 2 |       |       |       |       |  ...
           | 3 |       |       |       |       |  ...
           | 4 |       |       |       |       |  ...
           |...|  ...  |  ...  |  ...  |  ...  |  ...

       The headers are the letters and numbers at the top and the left of the worksheet. Since
       these headers serve mainly as a indication of position on the worksheet they generally do
       not appear on the printed page. If you wish to have them printed you can use the
       "print_row_col_headers()" method :

           $worksheet->print_row_col_headers();

       Do not confuse these headers with page headers as described in the "set_header()" section
       above.

   print_area($first_row, $first_col, $last_row, $last_col)
       This method is used to specify the area of the worksheet that will be printed. All four
       parameters must be specified. You can also use A1 notation, see the note about "Cell
       notation".

           $worksheet1->print_area('A1:H20');    # Cells A1 to H20
           $worksheet2->print_area(0, 0, 19, 7); # The same
           $worksheet2->print_area('A:H');       # Columns A to H if rows have data

   print_across()
       The "print_across" method is used to change the default print direction. This is referred
       to by Excel as the sheet "page order".

           $worksheet->print_across();

       The default page order is shown below for a worksheet that extends over 4 pages. The order
       is called "down then across":

           [1] [3]
           [2] [4]

       However, by using the "print_across" method the print order will be changed to "across
       then down":

           [1] [2]
           [3] [4]

   fit_to_pages($width, $height)
       The "fit_to_pages()" method is used to fit the printed area to a specific number of pages
       both vertically and horizontally. If the printed area exceeds the specified number of
       pages it will be scaled down to fit. This guarantees that the printed area will always
       appear on the specified number of pages even if the page size or margins change.

           $worksheet1->fit_to_pages(1, 1); # Fit to 1x1 pages
           $worksheet2->fit_to_pages(2, 1); # Fit to 2x1 pages
           $worksheet3->fit_to_pages(1, 2); # Fit to 1x2 pages

       The print area can be defined using the "print_area()" method as described above.

       A common requirement is to fit the printed output to n pages wide but have the height be
       as long as necessary. To achieve this set the $height to zero or leave it blank:

           $worksheet1->fit_to_pages(1, 0); # 1 page wide and as long as necessary
           $worksheet2->fit_to_pages(1);    # The same

       Note that although it is valid to use both "fit_to_pages()" and "set_print_scale()" on the
       same worksheet only one of these options can be active at a time. The last method call
       made will set the active option.

       Note that "fit_to_pages()" will override any manual page breaks that are defined in the
       worksheet.

   set_start_page($start_page)
       The "set_start_page()" method is used to set the number of the starting page when the
       worksheet is printed out. The default value is 1.

           $worksheet->set_start_page(2);

   set_print_scale($scale)
       Set the scale factor of the printed page. Scale factors in the range "10 <= $scale <= 400"
       are valid:

           $worksheet1->set_print_scale(50);
           $worksheet2->set_print_scale(75);
           $worksheet3->set_print_scale(300);
           $worksheet4->set_print_scale(400);

       The default scale factor is 100. Note, "set_print_scale()" does not affect the scale of
       the visible page in Excel. For that you should use "set_zoom()".

       Note also that although it is valid to use both "fit_to_pages()" and "set_print_scale()"
       on the same worksheet only one of these options can be active at a time. The last method
       call made will set the active option.

   set_h_pagebreaks(@breaks)
       Add horizontal page breaks to a worksheet. A page break causes all the data that follows
       it to be printed on the next page. Horizontal page breaks act between rows. To create a
       page break between rows 20 and 21 you must specify the break at row 21. However in zero
       index notation this is actually row 20. So you can pretend for a small while that you are
       using 1 index notation:

           $worksheet1->set_h_pagebreaks(20); # Break between row 20 and 21

       The "set_h_pagebreaks()" method will accept a list of page breaks and you can call it more
       than once:

           $worksheet2->set_h_pagebreaks( 20,  40,  60,  80, 100); # Add breaks
           $worksheet2->set_h_pagebreaks(120, 140, 160, 180, 200); # Add some more

       Note: If you specify the "fit to page" option via the "fit_to_pages()" method it will
       override all manual page breaks.

       There is a silent limitation of about 1000 horizontal page breaks per worksheet in line
       with an Excel internal limitation.

   set_v_pagebreaks(@breaks)
       Add vertical page breaks to a worksheet. A page break causes all the data that follows it
       to be printed on the next page. Vertical page breaks act between columns. To create a page
       break between columns 20 and 21 you must specify the break at column 21. However in zero
       index notation this is actually column 20. So you can pretend for a small while that you
       are using 1 index notation:

           $worksheet1->set_v_pagebreaks(20); # Break between column 20 and 21

       The "set_v_pagebreaks()" method will accept a list of page breaks and you can call it more
       than once:

           $worksheet2->set_v_pagebreaks( 20,  40,  60,  80, 100); # Add breaks
           $worksheet2->set_v_pagebreaks(120, 140, 160, 180, 200); # Add some more

       Note: If you specify the "fit to page" option via the "fit_to_pages()" method it will
       override all manual page breaks.

CELL FORMATTING

       This section describes the methods and properties that are available for formatting cells
       in Excel. The properties of a cell that can be formatted include: fonts, colours,
       patterns, borders, alignment and number formatting.

   Creating and using a Format object
       Cell formatting is defined through a Format object. Format objects are created by calling
       the workbook "add_format()" method as follows:

           my $format1 = $workbook->add_format();       # Set properties later
           my $format2 = $workbook->add_format(%props); # Set at creation

       The format object holds all the formatting properties that can be applied to a cell, a row
       or a column. The process of setting these properties is discussed in the next section.

       Once a Format object has been constructed and its properties have been set it can be
       passed as an argument to the worksheet "write" methods as follows:

           $worksheet->write(0, 0, 'One', $format);
           $worksheet->write_string(1, 0, 'Two', $format);
           $worksheet->write_number(2, 0, 3, $format);
           $worksheet->write_blank(3, 0, $format);

       Formats can also be passed to the worksheet "set_row()" and "set_column()" methods to
       define the default property for a row or column.

           $worksheet->set_row(0, 15, $format);
           $worksheet->set_column(0, 0, 15, $format);

   Format methods and Format properties
       The following table shows the Excel format categories, the formatting properties that can
       be applied and the equivalent object method:

           Category   Description       Property        Method Name
           --------   -----------       --------        -----------
           Font       Font type         font            set_font()
                      Font size         size            set_size()
                      Font color        color           set_color()
                      Bold              bold            set_bold()
                      Italic            italic          set_italic()
                      Underline         underline       set_underline()
                      Strikeout         font_strikeout  set_font_strikeout()
                      Super/Subscript   font_script     set_font_script()
                      Outline           font_outline    set_font_outline()
                      Shadow            font_shadow     set_font_shadow()

           Number     Numeric format    num_format      set_num_format()

           Protection Lock cells        locked          set_locked()
                      Hide formulas     hidden          set_hidden()

           Alignment  Horizontal align  align           set_align()
                      Vertical align    valign          set_align()
                      Rotation          rotation        set_rotation()
                      Text wrap         text_wrap       set_text_wrap()
                      Justify last      text_justlast   set_text_justlast()
                      Center across     center_across   set_center_across()
                      Indentation       indent          set_indent()
                      Shrink to fit     shrink          set_shrink()

           Pattern    Cell pattern      pattern         set_pattern()
                      Background color  bg_color        set_bg_color()
                      Foreground color  fg_color        set_fg_color()

           Border     Cell border       border          set_border()
                      Bottom border     bottom          set_bottom()
                      Top border        top             set_top()
                      Left border       left            set_left()
                      Right border      right           set_right()
                      Border color      border_color    set_border_color()
                      Bottom color      bottom_color    set_bottom_color()
                      Top color         top_color       set_top_color()
                      Left color        left_color      set_left_color()
                      Right color       right_color     set_right_color()

       There are two ways of setting Format properties: by using the object method interface or
       by setting the property directly. For example, a typical use of the method interface would
       be as follows:

           my $format = $workbook->add_format();
           $format->set_bold();
           $format->set_color('red');

       By comparison the properties can be set directly by passing a hash of properties to the
       Format constructor:

           my $format = $workbook->add_format(bold => 1, color => 'red');

       or after the Format has been constructed by means of the "set_format_properties()" method
       as follows:

           my $format = $workbook->add_format();
           $format->set_format_properties(bold => 1, color => 'red');

       You can also store the properties in one or more named hashes and pass them to the
       required method:

           my %font    = (
                           font  => 'Arial',
                           size  => 12,
                           color => 'blue',
                           bold  => 1,
                         );

           my %shading = (
                           bg_color => 'green',
                           pattern  => 1,
                         );

           my $format1 = $workbook->add_format(%font);           # Font only
           my $format2 = $workbook->add_format(%font, %shading); # Font and shading

       The provision of two ways of setting properties might lead you to wonder which is the best
       way. The method mechanism may be better is you prefer setting properties via method calls
       (which the author did when the code was first written) otherwise passing properties to the
       constructor has proved to be a little more flexible and self documenting in practice. An
       additional advantage of working with property hashes is that it allows you to share
       formatting between workbook objects as shown in the example above.

       The Perl/Tk style of adding properties is also supported:

           my %font    = (
                           -font      => 'Arial',
                           -size      => 12,
                           -color     => 'blue',
                           -bold      => 1,
                         );

   Working with formats
       The default format is Arial 10 with all other properties off.

       Each unique format in Spreadsheet::WriteExcel must have a corresponding Format object. It
       isn't possible to use a Format with a write() method and then redefine the Format for use
       at a later stage. This is because a Format is applied to a cell not in its current state
       but in its final state. Consider the following example:

           my $format = $workbook->add_format();
           $format->set_bold();
           $format->set_color('red');
           $worksheet->write('A1', 'Cell A1', $format);
           $format->set_color('green');
           $worksheet->write('B1', 'Cell B1', $format);

       Cell A1 is assigned the Format $format which is initially set to the colour red. However,
       the colour is subsequently set to green. When Excel displays Cell A1 it will display the
       final state of the Format which in this case will be the colour green.

       In general a method call without an argument will turn a property on, for example:

           my $format1 = $workbook->add_format();
           $format1->set_bold();  # Turns bold on
           $format1->set_bold(1); # Also turns bold on
           $format1->set_bold(0); # Turns bold off

FORMAT METHODS

       The Format object methods are described in more detail in the following sections. In
       addition, there is a Perl program called "formats.pl" in the "examples" directory of the
       WriteExcel distribution. This program creates an Excel workbook called "formats.xls" which
       contains examples of almost all the format types.

       The following Format methods are available:

           set_font()
           set_size()
           set_color()
           set_bold()
           set_italic()
           set_underline()
           set_font_strikeout()
           set_font_script()
           set_font_outline()
           set_font_shadow()
           set_num_format()
           set_locked()
           set_hidden()
           set_align()
           set_rotation()
           set_text_wrap()
           set_text_justlast()
           set_center_across()
           set_indent()
           set_shrink()
           set_pattern()
           set_bg_color()
           set_fg_color()
           set_border()
           set_bottom()
           set_top()
           set_left()
           set_right()
           set_border_color()
           set_bottom_color()
           set_top_color()
           set_left_color()
           set_right_color()

       The above methods can also be applied directly as properties. For example
       "$format->set_bold()" is equivalent to "$workbook->add_format(bold => 1)".

   set_format_properties(%properties)
       The properties of an existing Format object can be also be set by means of
       "set_format_properties()":

           my $format = $workbook->add_format();
           $format->set_format_properties(bold => 1, color => 'red');

       However, this method is here mainly for legacy reasons. It is preferable to set the
       properties in the format constructor:

           my $format = $workbook->add_format(bold => 1, color => 'red');

   set_font($fontname)
           Default state:      Font is Arial
           Default action:     None
           Valid args:         Any valid font name

       Specify the font used:

           $format->set_font('Times New Roman');

       Excel can only display fonts that are installed on the system that it is running on.
       Therefore it is best to use the fonts that come as standard such as 'Arial', 'Times New
       Roman' and 'Courier New'. See also the Fonts worksheet created by formats.pl

   set_size()
           Default state:      Font size is 10
           Default action:     Set font size to 1
           Valid args:         Integer values from 1 to as big as your screen.

       Set the font size. Excel adjusts the height of a row to accommodate the largest font size
       in the row. You can also explicitly specify the height of a row using the set_row()
       worksheet method.

           my $format = $workbook->add_format();
           $format->set_size(30);

   set_color()
           Default state:      Excels default color, usually black
           Default action:     Set the default color
           Valid args:         Integers from 8..63 or the following strings:
                               'black'
                               'blue'
                               'brown'
                               'cyan'
                               'gray'
                               'green'
                               'lime'
                               'magenta'
                               'navy'
                               'orange'
                               'pink'
                               'purple'
                               'red'
                               'silver'
                               'white'
                               'yellow'

       Set the font colour. The "set_color()" method is used as follows:

           my $format = $workbook->add_format();
           $format->set_color('red');
           $worksheet->write(0, 0, 'wheelbarrow', $format);

       Note: The "set_color()" method is used to set the colour of the font in a cell. To set the
       colour of a cell use the "set_bg_color()" and "set_pattern()" methods.

       For additional examples see the 'Named colors' and 'Standard colors' worksheets created by
       formats.pl in the examples directory.

       See also "COLOURS IN EXCEL".

   set_bold()
           Default state:      bold is off
           Default action:     Turn bold on
           Valid args:         0, 1 [1]

       Set the bold property of the font:

           $format->set_bold();  # Turn bold on

       [1] Actually, values in the range 100..1000 are also valid. 400 is normal, 700 is bold and
       1000 is very bold indeed. It is probably best to set the value to 1 and use normal bold.

   set_italic()
           Default state:      Italic is off
           Default action:     Turn italic on
           Valid args:         0, 1

       Set the italic property of the font:

           $format->set_italic();  # Turn italic on

   set_underline()
           Default state:      Underline is off
           Default action:     Turn on single underline
           Valid args:         0  = No underline
                               1  = Single underline
                               2  = Double underline
                               33 = Single accounting underline
                               34 = Double accounting underline

       Set the underline property of the font.

           $format->set_underline();   # Single underline

   set_font_strikeout()
           Default state:      Strikeout is off
           Default action:     Turn strikeout on
           Valid args:         0, 1

       Set the strikeout property of the font.

   set_font_script()
           Default state:      Super/Subscript is off
           Default action:     Turn Superscript on
           Valid args:         0  = Normal
                               1  = Superscript
                               2  = Subscript

       Set the superscript/subscript property of the font. This format is currently not very
       useful.

   set_font_outline()
           Default state:      Outline is off
           Default action:     Turn outline on
           Valid args:         0, 1

       Macintosh only.

   set_font_shadow()
           Default state:      Shadow is off
           Default action:     Turn shadow on
           Valid args:         0, 1

       Macintosh only.

   set_num_format()
           Default state:      General format
           Default action:     Format index 1
           Valid args:         See the following table

       This method is used to define the numerical format of a number in Excel. It controls
       whether a number is displayed as an integer, a floating point number, a date, a currency
       value or some other user defined format.

       The numerical format of a cell can be specified by using a format string or an index to
       one of Excel's built-in formats:

           my $format1 = $workbook->add_format();
           my $format2 = $workbook->add_format();
           $format1->set_num_format('d mmm yyyy'); # Format string
           $format2->set_num_format(0x0f);         # Format index

           $worksheet->write(0, 0, 36892.521, $format1);      # 1 Jan 2001
           $worksheet->write(0, 0, 36892.521, $format2);      # 1-Jan-01

       Using format strings you can define very sophisticated formatting of numbers.

           $format01->set_num_format('0.000');
           $worksheet->write(0,  0, 3.1415926, $format01);    # 3.142

           $format02->set_num_format('#,##0');
           $worksheet->write(1,  0, 1234.56,   $format02);    # 1,235

           $format03->set_num_format('#,##0.00');
           $worksheet->write(2,  0, 1234.56,   $format03);    # 1,234.56

           $format04->set_num_format('$0.00');
           $worksheet->write(3,  0, 49.99,     $format04);    # $49.99

           # Note you can use other currency symbols such as the pound or yen as well.
           # Other currencies may require the use of Unicode.

           $format07->set_num_format('mm/dd/yy');
           $worksheet->write(6,  0, 36892.521, $format07);    # 01/01/01

           $format08->set_num_format('mmm d yyyy');
           $worksheet->write(7,  0, 36892.521, $format08);    # Jan 1 2001

           $format09->set_num_format('d mmmm yyyy');
           $worksheet->write(8,  0, 36892.521, $format09);    # 1 January 2001

           $format10->set_num_format('dd/mm/yyyy hh:mm AM/PM');
           $worksheet->write(9,  0, 36892.521, $format10);    # 01/01/2001 12:30 AM

           $format11->set_num_format('0 "dollar and" .00 "cents"');
           $worksheet->write(10, 0, 1.87,      $format11);    # 1 dollar and .87 cents

           # Conditional formatting
           $format12->set_num_format('[Green]General;[Red]-General;General');
           $worksheet->write(11, 0, 123,       $format12);    # > 0 Green
           $worksheet->write(12, 0, -45,       $format12);    # < 0 Red
           $worksheet->write(13, 0, 0,         $format12);    # = 0 Default colour

           # Zip code
           $format13->set_num_format('00000');
           $worksheet->write(14, 0, '01209',   $format13);

       The number system used for dates is described in "DATES AND TIME IN EXCEL".

       The colour format should have one of the following values:

           [Black] [Blue] [Cyan] [Green] [Magenta] [Red] [White] [Yellow]

       Alternatively you can specify the colour based on a colour index as follows: "[Color n]",
       where n is a standard Excel colour index - 7. See the 'Standard colors' worksheet created
       by formats.pl.

       For more information refer to the documentation on formatting in the "docs" directory of
       the Spreadsheet::WriteExcel distro, the Excel on-line help or
       <http://office.microsoft.com/en-gb/assistance/HP051995001033.aspx>.

       You should ensure that the format string is valid in Excel prior to using it in
       WriteExcel.

       Excel's built-in formats are shown in the following table:

           Index   Index   Format String
           0       0x00    General
           1       0x01    0
           2       0x02    0.00
           3       0x03    #,##0
           4       0x04    #,##0.00
           5       0x05    ($#,##0_);($#,##0)
           6       0x06    ($#,##0_);[Red]($#,##0)
           7       0x07    ($#,##0.00_);($#,##0.00)
           8       0x08    ($#,##0.00_);[Red]($#,##0.00)
           9       0x09    0%
           10      0x0a    0.00%
           11      0x0b    0.00E+00
           12      0x0c    # ?/?
           13      0x0d    # ??/??
           14      0x0e    m/d/yy
           15      0x0f    d-mmm-yy
           16      0x10    d-mmm
           17      0x11    mmm-yy
           18      0x12    h:mm AM/PM
           19      0x13    h:mm:ss AM/PM
           20      0x14    h:mm
           21      0x15    h:mm:ss
           22      0x16    m/d/yy h:mm
           ..      ....    ...........
           37      0x25    (#,##0_);(#,##0)
           38      0x26    (#,##0_);[Red](#,##0)
           39      0x27    (#,##0.00_);(#,##0.00)
           40      0x28    (#,##0.00_);[Red](#,##0.00)
           41      0x29    _(* #,##0_);_(* (#,##0);_(* "-"_);_(@_)
           42      0x2a    _($* #,##0_);_($* (#,##0);_($* "-"_);_(@_)
           43      0x2b    _(* #,##0.00_);_(* (#,##0.00);_(* "-"??_);_(@_)
           44      0x2c    _($* #,##0.00_);_($* (#,##0.00);_($* "-"??_);_(@_)
           45      0x2d    mm:ss
           46      0x2e    [h]:mm:ss
           47      0x2f    mm:ss.0
           48      0x30    ##0.0E+0
           49      0x31    @

       For examples of these formatting codes see the 'Numerical formats' worksheet created by
       formats.pl. See also the number_formats1.html and the number_formats2.html documents in
       the "docs" directory of the distro.

       Note 1. Numeric formats 23 to 36 are not documented by Microsoft and may differ in
       international versions.

       Note 2. In Excel 5 the dollar sign appears as a dollar sign. In Excel 97-2000 it appears
       as the defined local currency symbol.

       Note 3. The red negative numeric formats display slightly differently in Excel 5 and Excel
       97-2000.

   set_locked()
           Default state:      Cell locking is on
           Default action:     Turn locking on
           Valid args:         0, 1

       This property can be used to prevent modification of a cells contents. Following Excel's
       convention, cell locking is turned on by default. However, it only has an effect if the
       worksheet has been protected, see the worksheet "protect()" method.

           my $locked  = $workbook->add_format();
           $locked->set_locked(1); # A non-op

           my $unlocked = $workbook->add_format();
           $locked->set_locked(0);

           # Enable worksheet protection
           $worksheet->protect();

           # This cell cannot be edited.
           $worksheet->write('A1', '=1+2', $locked);

           # This cell can be edited.
           $worksheet->write('A2', '=1+2', $unlocked);

       Note: This offers weak protection even with a password, see the note in relation to the
       "protect()" method.

   set_hidden()
           Default state:      Formula hiding is off
           Default action:     Turn hiding on
           Valid args:         0, 1

       This property is used to hide a formula while still displaying its result. This is
       generally used to hide complex calculations from end users who are only interested in the
       result. It only has an effect if the worksheet has been protected, see the worksheet
       "protect()" method.

           my $hidden = $workbook->add_format();
           $hidden->set_hidden();

           # Enable worksheet protection
           $worksheet->protect();

           # The formula in this cell isn't visible
           $worksheet->write('A1', '=1+2', $hidden);

       Note: This offers weak protection even with a password, see the note in relation to the
       "protect()" method.

   set_align()
           Default state:      Alignment is off
           Default action:     Left alignment
           Valid args:         'left'              Horizontal
                               'center'
                               'right'
                               'fill'
                               'justify'
                               'center_across'

                               'top'               Vertical
                               'vcenter'
                               'bottom'
                               'vjustify'

       This method is used to set the horizontal and vertical text alignment within a cell.
       Vertical and horizontal alignments can be combined. The method is used as follows:

           my $format = $workbook->add_format();
           $format->set_align('center');
           $format->set_align('vcenter');
           $worksheet->set_row(0, 30);
           $worksheet->write(0, 0, 'X', $format);

       Text can be aligned across two or more adjacent cells using the "center_across" property.
       However, for genuine merged cells it is better to use the "merge_range()" worksheet
       method.

       The "vjustify" (vertical justify) option can be used to provide automatic text wrapping in
       a cell. The height of the cell will be adjusted to accommodate the wrapped text. To
       specify where the text wraps use the "set_text_wrap()" method.

       For further examples see the 'Alignment' worksheet created by formats.pl.

   set_center_across()
           Default state:      Center across selection is off
           Default action:     Turn center across on
           Valid args:         1

       Text can be aligned across two or more adjacent cells using the "set_center_across()"
       method. This is an alias for the "set_align('center_across')" method call.

       Only one cell should contain the text, the other cells should be blank:

           my $format = $workbook->add_format();
           $format->set_center_across();

           $worksheet->write(1, 1, 'Center across selection', $format);
           $worksheet->write_blank(1, 2, $format);

       See also the "merge1.pl" to "merge6.pl" programs in the "examples" directory and the
       "merge_range()" method.

   set_text_wrap()
           Default state:      Text wrap is off
           Default action:     Turn text wrap on
           Valid args:         0, 1

       Here is an example using the text wrap property, the escape character "\n" is used to
       indicate the end of line:

           my $format = $workbook->add_format();
           $format->set_text_wrap();
           $worksheet->write(0, 0, "It's\na bum\nwrap", $format);

       Excel will adjust the height of the row to accommodate the wrapped text. A similar effect
       can be obtained without newlines using the "set_align('vjustify')" method. See the
       "textwrap.pl" program in the "examples" directory.

   set_rotation()
           Default state:      Text rotation is off
           Default action:     None
           Valid args:         Integers in the range -90 to 90 and 270

       Set the rotation of the text in a cell. The rotation can be any angle in the range -90 to
       90 degrees.

           my $format = $workbook->add_format();
           $format->set_rotation(30);
           $worksheet->write(0, 0, 'This text is rotated', $format);

       The angle 270 is also supported. This indicates text where the letters run from top to
       bottom.

   set_indent()
           Default state:      Text indentation is off
           Default action:     Indent text 1 level
           Valid args:         Positive integers

       This method can be used to indent text. The argument, which should be an integer, is taken
       as the level of indentation:

           my $format = $workbook->add_format();
           $format->set_indent(2);
           $worksheet->write(0, 0, 'This text is indented', $format);

       Indentation is a horizontal alignment property. It will override any other horizontal
       properties but it can be used in conjunction with vertical properties.

   set_shrink()
           Default state:      Text shrinking is off
           Default action:     Turn "shrink to fit" on
           Valid args:         1

       This method can be used to shrink text so that it fits in a cell.

           my $format = $workbook->add_format();
           $format->set_shrink();
           $worksheet->write(0, 0, 'Honey, I shrunk the text!', $format);

   set_text_justlast()
           Default state:      Justify last is off
           Default action:     Turn justify last on
           Valid args:         0, 1

       Only applies to Far Eastern versions of Excel.

   set_pattern()
           Default state:      Pattern is off
           Default action:     Solid fill is on
           Valid args:         0 .. 18

       Set the background pattern of a cell.

       Examples of the available patterns are shown in the 'Patterns' worksheet created by
       formats.pl. However, it is unlikely that you will ever need anything other than Pattern 1
       which is a solid fill of the background color.

   set_bg_color()
           Default state:      Color is off
           Default action:     Solid fill.
           Valid args:         See set_color()

       The "set_bg_color()" method can be used to set the background colour of a pattern.
       Patterns are defined via the "set_pattern()" method. If a pattern hasn't been defined then
       a solid fill pattern is used as the default.

       Here is an example of how to set up a solid fill in a cell:

           my $format = $workbook->add_format();

           $format->set_pattern(); # This is optional when using a solid fill

           $format->set_bg_color('green');
           $worksheet->write('A1', 'Ray', $format);

       For further examples see the 'Patterns' worksheet created by formats.pl.

   set_fg_color()
           Default state:      Color is off
           Default action:     Solid fill.
           Valid args:         See set_color()

       The "set_fg_color()" method can be used to set the foreground colour of a pattern.

       For further examples see the 'Patterns' worksheet created by formats.pl.

   set_border()
           Also applies to:    set_bottom()
                               set_top()
                               set_left()
                               set_right()

           Default state:      Border is off
           Default action:     Set border type 1
           Valid args:         0-13, See below.

       A cell border is comprised of a border on the bottom, top, left and right. These can be
       set to the same value using "set_border()" or individually using the relevant method calls
       shown above.

       The following shows the border styles sorted by Spreadsheet::WriteExcel index number:

           Index   Name            Weight   Style
           =====   =============   ======   ===========
           0       None            0
           1       Continuous      1        -----------
           2       Continuous      2        -----------
           3       Dash            1        - - - - - -
           4       Dot             1        . . . . . .
           5       Continuous      3        -----------
           6       Double          3        ===========
           7       Continuous      0        -----------
           8       Dash            2        - - - - - -
           9       Dash Dot        1        - . - . - .
           10      Dash Dot        2        - . - . - .
           11      Dash Dot Dot    1        - . . - . .
           12      Dash Dot Dot    2        - . . - . .
           13      SlantDash Dot   2        / - . / - .

       The following shows the borders sorted by style:

           Name            Weight   Style         Index
           =============   ======   ===========   =====
           Continuous      0        -----------   7
           Continuous      1        -----------   1
           Continuous      2        -----------   2
           Continuous      3        -----------   5
           Dash            1        - - - - - -   3
           Dash            2        - - - - - -   8
           Dash Dot        1        - . - . - .   9
           Dash Dot        2        - . - . - .   10
           Dash Dot Dot    1        - . . - . .   11
           Dash Dot Dot    2        - . . - . .   12
           Dot             1        . . . . . .   4
           Double          3        ===========   6
           None            0                      0
           SlantDash Dot   2        / - . / - .   13

       The following shows the borders in the order shown in the Excel Dialog.

           Index   Style             Index   Style
           =====   =====             =====   =====
           0       None              12      - . . - . .
           7       -----------       13      / - . / - .
           4       . . . . . .       10      - . - . - .
           11      - . . - . .       8       - - - - - -
           9       - . - . - .       2       -----------
           3       - - - - - -       5       -----------
           1       -----------       6       ===========

       Examples of the available border styles are shown in the 'Borders' worksheet created by
       formats.pl.

   set_border_color()
           Also applies to:    set_bottom_color()
                               set_top_color()
                               set_left_color()
                               set_right_color()

           Default state:      Color is off
           Default action:     Undefined
           Valid args:         See set_color()

       Set the colour of the cell borders. A cell border is comprised of a border on the bottom,
       top, left and right. These can be set to the same colour using "set_border_color()" or
       individually using the relevant method calls shown above. Examples of the border styles
       and colours are shown in the 'Borders' worksheet created by formats.pl.

   copy($format)
       This method is used to copy all of the properties from one Format object to another:

           my $lorry1 = $workbook->add_format();
           $lorry1->set_bold();
           $lorry1->set_italic();
           $lorry1->set_color('red');    # lorry1 is bold, italic and red

           my $lorry2 = $workbook->add_format();
           $lorry2->copy($lorry1);
           $lorry2->set_color('yellow'); # lorry2 is bold, italic and yellow

       The "copy()" method is only useful if you are using the method interface to Format
       properties. It generally isn't required if you are setting Format properties directly
       using hashes.

       Note: this is not a copy constructor, both objects must exist prior to copying.

UNICODE IN EXCEL

       The following is a brief introduction to handling Unicode in "Spreadsheet::WriteExcel".

       For a more general introduction to Unicode handling in Perl see perlunitut and
       perluniintro.

       When using Spreadsheet::WriteExcel the best and easiest way to write unicode strings to an
       Excel file is to use "UTF-8" encoded strings and perl 5.8 (or later).
       Spreadsheet::WriteExcel also allows you to write unicode strings using older perls but it
       generally requires more work, as explained below.

       Internally, Excel encodes unicode data as "UTF-16LE" (where LE means little-endian). If
       you are using perl 5.8+ then Spreadsheet::WriteExcel will convert "UTF-8" strings to
       "UTF-16LE" when required. No further intervention is required from the programmer, for
       example:

           # perl 5.8+ example:
           my $smiley = "\x{263A}";

           $worksheet->write('A1', 'Hello world'); # ASCII
           $worksheet->write('A2', $smiley);       # UTF-8

       Spreadsheet::WriteExcel also lets you write unicode data as "UTF-16". Since the majority
       of CPAN modules default to "UTF-16BE" (big-endian) Spreadsheet::WriteExcel also uses
       "UTF-16BE" and converts it internally to "UTF-16LE":

           # perl 5.005 example:
           my $smiley = pack 'n', 0x263A;

           $worksheet->write               ('A3', 'Hello world'); # ASCII
           $worksheet->write_utf16be_string('A4', $smiley);       # UTF-16

       Although the above examples look similar there is an important difference. With "uft8" and
       perl 5.8+ Spreadsheet::WriteExcel treats "UTF-8" strings in exactly the same way as any
       other string. However, with "UTF16" data we need to distinguish it from other strings
       either by calling a separate function or by passing an additional flag to indicate the
       data type.

       If you are dealing with non-ASCII characters that aren't in "UTF-8" then perl 5.8+
       provides useful tools in the guise of the "Encode" module to help you to convert to the
       required format. For example:

           use Encode 'decode';

           my $string = 'some string with koi8-r characters';
              $string = decode('koi8-r', $string); # koi8-r to utf8

       Alternatively you can read data from an encoded file and convert it to "UTF-8" as you read
       it in:

           my $file = 'unicode_koi8r.txt';
           open FH, '<:encoding(koi8-r)', $file  or die "Couldn't open $file: $!\n";

           my $row = 0;
           while (<FH>) {
               # Data read in is now in utf8 format.
               chomp;
               $worksheet->write($row++, 0,  $_);
           }

       These methodologies are explained in more detail in perlunitut, perluniintro and
       perlunicode.

       See also the "unicode_*.pl" programs in the examples directory of the distro.

COLOURS IN EXCEL

       Excel provides a colour palette of 56 colours. In Spreadsheet::WriteExcel these colours
       are accessed via their palette index in the range 8..63. This index is used to set the
       colour of fonts, cell patterns and cell borders. For example:

           my $format = $workbook->add_format(
                                               color => 12, # index for blue
                                               font  => 'Arial',
                                               size  => 12,
                                               bold  => 1,
                                            );

       The most commonly used colours can also be accessed by name. The name acts as a simple
       alias for the colour index:

           black     =>    8
           blue      =>   12
           brown     =>   16
           cyan      =>   15
           gray      =>   23
           green     =>   17
           lime      =>   11
           magenta   =>   14
           navy      =>   18
           orange    =>   53
           pink      =>   33
           purple    =>   20
           red       =>   10
           silver    =>   22
           white     =>    9
           yellow    =>   13

       For example:

           my $font = $workbook->add_format(color => 'red');

       Users of VBA in Excel should note that the equivalent colour indices are in the range
       1..56 instead of 8..63.

       If the default palette does not provide a required colour you can override one of the
       built-in values. This is achieved by using the "set_custom_color()" workbook method to
       adjust the RGB (red green blue) components of the colour:

           my $ferrari = $workbook->set_custom_color(40, 216, 12, 12);

           my $format  = $workbook->add_format(
                                               bg_color => $ferrari,
                                               pattern  => 1,
                                               border   => 1
                                             );

           $worksheet->write_blank('A1', $format);

       The default Excel colour palette is shown in "palette.html" in the "docs" directory  of
       the distro. You can generate an Excel version of the palette using "colors.pl" in the
       "examples" directory.

DATES AND TIME IN EXCEL

       There are two important things to understand about dates and times in Excel:

       1 A date/time in Excel is a real number plus an Excel number format.
       2 Spreadsheet::WriteExcel doesn't automatically convert date/time strings in "write()" to
       an Excel date/time.

       These two points are explained in more detail below along with some suggestions on how to
       convert times and dates to the required format.

   An Excel date/time is a number plus a format
       If you write a date string with "write()" then all you will get is a string:

           $worksheet->write('A1', '02/03/04'); # !! Writes a string not a date. !!

       Dates and times in Excel are represented by real numbers, for example "Jan 1 2001 12:30
       AM" is represented by the number 36892.521.

       The integer part of the number stores the number of days since the epoch and the
       fractional part stores the percentage of the day.

       A date or time in Excel is just like any other number. To have the number display as a
       date you must apply an Excel number format to it. Here are some examples.

           #!/usr/bin/perl -w

           use strict;
           use Spreadsheet::WriteExcel;

           my $workbook  = Spreadsheet::WriteExcel->new('date_examples.xls');
           my $worksheet = $workbook->add_worksheet();

           $worksheet->set_column('A:A', 30); # For extra visibility.

           my $number    = 39506.5;

           $worksheet->write('A1', $number);            #     39506.5

           my $format2 = $workbook->add_format(num_format => 'dd/mm/yy');
           $worksheet->write('A2', $number , $format2); #     28/02/08

           my $format3 = $workbook->add_format(num_format => 'mm/dd/yy');
           $worksheet->write('A3', $number , $format3); #     02/28/08

           my $format4 = $workbook->add_format(num_format => 'd-m-yyyy');
           $worksheet->write('A4', $number , $format4); #     28-2-2008

           my $format5 = $workbook->add_format(num_format => 'dd/mm/yy hh:mm');
           $worksheet->write('A5', $number , $format5); #     28/02/08 12:00

           my $format6 = $workbook->add_format(num_format => 'd mmm yyyy');
           $worksheet->write('A6', $number , $format6); #     28 Feb 2008

           my $format7 = $workbook->add_format(num_format => 'mmm d yyyy hh:mm AM/PM');
           $worksheet->write('A7', $number , $format7); #     Feb 28 2008 12:00 PM

   Spreadsheet::WriteExcel doesn't automatically convert date/time strings
       Spreadsheet::WriteExcel doesn't automatically convert input date strings into Excel's
       formatted date numbers due to the large number of possible date formats and also due to
       the possibility of misinterpretation.

       For example, does "02/03/04" mean March 2 2004, February 3 2004 or even March 4 2002.

       Therefore, in order to handle dates you will have to convert them to numbers and apply an
       Excel format. Some methods for converting dates are listed in the next section.

       The most direct way is to convert your dates to the ISO8601 "yyyy-mm-ddThh:mm:ss.sss" date
       format and use the "write_date_time()" worksheet method:

           $worksheet->write_date_time('A2', '2001-01-01T12:20', $format);

       See the "write_date_time()" section of the documentation for more details.

       A general methodology for handling date strings with "write_date_time()" is:

           1. Identify incoming date/time strings with a regex.
           2. Extract the component parts of the date/time using the same regex.
           3. Convert the date/time to the ISO8601 format.
           4. Write the date/time using write_date_time() and a number format.

       Here is an example:

           #!/usr/bin/perl -w

           use strict;
           use Spreadsheet::WriteExcel;

           my $workbook    = Spreadsheet::WriteExcel->new('example.xls');
           my $worksheet   = $workbook->add_worksheet();

           # Set the default format for dates.
           my $date_format = $workbook->add_format(num_format => 'mmm d yyyy');

           # Increase column width to improve visibility of data.
           $worksheet->set_column('A:C', 20);

           # Simulate reading from a data source.
           my $row = 0;

           while (<DATA>) {
               chomp;

               my $col  = 0;
               my @data = split ' ';

               for my $item (@data) {

                   # Match dates in the following formats: d/m/yy, d/m/yyyy
                   if ($item =~ qr[^(\d{1,2})/(\d{1,2})/(\d{4})$]) {

                       # Change to the date format required by write_date_time().
                       my $date = sprintf "%4d-%02d-%02dT", $3, $2, $1;

                       $worksheet->write_date_time($row, $col++, $date, $date_format);
                   }
                   else {
                       # Just plain data
                       $worksheet->write($row, $col++, $item);
                   }
               }
               $row++;
           }

           __DATA__
           Item    Cost    Date
           Book    10      1/9/2007
           Beer    4       12/9/2007
           Bed     500     5/10/2007

       For a slightly more advanced solution you can modify the "write()" method to handle date
       formats of your choice via the "add_write_handler()" method. See the "add_write_handler()"
       section of the docs and the write_handler3.pl and write_handler4.pl programs in the
       examples directory of the distro.

   Converting dates and times to an Excel date or time
       The "write_date_time()" method above is just one way of handling dates and times.

       The Spreadsheet::WriteExcel::Utility module which is included in the distro has date/time
       handling functions:

           use Spreadsheet::WriteExcel::Utility;

           $date           = xl_date_list(2002, 1, 1);         # 37257
           $date           = xl_parse_date("11 July 1997");    # 35622
           $time           = xl_parse_time('3:21:36 PM');      # 0.64
           $date           = xl_decode_date_EU("13 May 2002"); # 37389

       Note: some of these functions require additional CPAN modules.

       For date conversions using the CPAN "DateTime" framework see DateTime::Format::Excel
       <http://search.cpan.org/search?dist=DateTime-Format-Excel>.

OUTLINES AND GROUPING IN EXCEL

       Excel allows you to group rows or columns so that they can be hidden or displayed with a
       single mouse click. This feature is referred to as outlines.

       Outlines can reduce complex data down to a few salient sub-totals or summaries.

       This feature is best viewed in Excel but the following is an ASCII representation of what
       a worksheet with three outlines might look like. Rows 3-4 and rows 7-8 are grouped at
       level 2. Rows 2-9 are grouped at level 1. The lines at the left hand side are called
       outline level bars.

                   ------------------------------------------
            1 2 3 |   |   A   |   B   |   C   |   D   |  ...
                   ------------------------------------------
             _    | 1 |   A   |       |       |       |  ...
            |  _  | 2 |   B   |       |       |       |  ...
            | |   | 3 |  (C)  |       |       |       |  ...
            | |   | 4 |  (D)  |       |       |       |  ...
            | -   | 5 |   E   |       |       |       |  ...
            |  _  | 6 |   F   |       |       |       |  ...
            | |   | 7 |  (G)  |       |       |       |  ...
            | |   | 8 |  (H)  |       |       |       |  ...
            | -   | 9 |   I   |       |       |       |  ...
            -     | . |  ...  |  ...  |  ...  |  ...  |  ...

       Clicking the minus sign on each of the level 2 outlines will collapse and hide the data as
       shown in the next figure. The minus sign changes to a plus sign to indicate that the data
       in the outline is hidden.

                   ------------------------------------------
            1 2 3 |   |   A   |   B   |   C   |   D   |  ...
                   ------------------------------------------
             _    | 1 |   A   |       |       |       |  ...
            |     | 2 |   B   |       |       |       |  ...
            | +   | 5 |   E   |       |       |       |  ...
            |     | 6 |   F   |       |       |       |  ...
            | +   | 9 |   I   |       |       |       |  ...
            -     | . |  ...  |  ...  |  ...  |  ...  |  ...

       Clicking on the minus sign on the level 1 outline will collapse the remaining rows as
       follows:

                   ------------------------------------------
            1 2 3 |   |   A   |   B   |   C   |   D   |  ...
                   ------------------------------------------
                  | 1 |   A   |       |       |       |  ...
            +     | . |  ...  |  ...  |  ...  |  ...  |  ...

       Grouping in "Spreadsheet::WriteExcel" is achieved by setting the outline level via the
       "set_row()" and "set_column()" worksheet methods:

           set_row($row, $height, $format, $hidden, $level, $collapsed)
           set_column($first_col, $last_col, $width, $format, $hidden, $level, $collapsed)

       The following example sets an outline level of 1 for rows 1 and 2 (zero-indexed) and
       columns B to G. The parameters $height and $XF are assigned default values since they are
       undefined:

           $worksheet->set_row(1, undef, undef, 0, 1);
           $worksheet->set_row(2, undef, undef, 0, 1);
           $worksheet->set_column('B:G', undef, undef, 0, 1);

       Excel allows up to 7 outline levels. Therefore the $level parameter should be in the range
       "0 <= $level <= 7".

       Rows and columns can be collapsed by setting the $hidden flag for the hidden rows/columns
       and setting the $collapsed flag for the row/column that has the collapsed "+" symbol:

           $worksheet->set_row(1, undef, undef, 1, 1);
           $worksheet->set_row(2, undef, undef, 1, 1);
           $worksheet->set_row(3, undef, undef, 0, 0, 1);        # Collapsed flag.

           $worksheet->set_column('B:G', undef, undef, 1, 1);
           $worksheet->set_column('H:H', undef, undef, 0, 0, 1); # Collapsed flag.

       Note: Setting the $collapsed flag is particularly important for compatibility with
       OpenOffice.org and Gnumeric.

       For a more complete example see the "outline.pl" and "outline_collapsed.pl" programs in
       the examples directory of the distro.

       Some additional outline properties can be set via the "outline_settings()" worksheet
       method, see above.

DATA VALIDATION IN EXCEL

       Data validation is a feature of Excel which allows you to restrict the data that a users
       enters in a cell and to display help and warning messages. It also allows you to restrict
       input to values in a drop down list.

       A typical use case might be to restrict data in a cell to integer values in a certain
       range, to provide a help message to indicate the required value and to issue a warning if
       the input data doesn't meet the stated criteria. In Spreadsheet::WriteExcel we could do
       that as follows:

           $worksheet->data_validation('B3',
               {
                   validate        => 'integer',
                   criteria        => 'between',
                   minimum         => 1,
                   maximum         => 100,
                   input_title     => 'Input an integer:',
                   input_message   => 'Between 1 and 100',
                   error_message   => 'Sorry, try again.',
               });

       The above example would look like this in Excel:
       <http://homepage.eircom.net/~jmcnamara/perl/data_validation.jpg>.

       For more information on data validation see the following Microsoft support article
       "Description and examples of data validation in Excel":
       <http://support.microsoft.com/kb/211485>.

       The following sections describe how to use the "data_validation()" method and its various
       options.

   data_validation($row, $col, { parameter => 'value', ... })
       The "data_validation()" method is used to construct an Excel data validation.

       It can be applied to a single cell or a range of cells. You can pass 3 parameters such as
       "($row, $col, {...})" or 5 parameters such as "($first_row, $first_col, $last_row,
       $last_col, {...})". You can also use "A1" style notation. For example:

           $worksheet->data_validation(0, 0,       {...});
           $worksheet->data_validation(0, 0, 4, 1, {...});

           # Which are the same as:

           $worksheet->data_validation('A1',       {...});
           $worksheet->data_validation('A1:B5',    {...});

       See also the note about "Cell notation" for more information.

       The last parameter in "data_validation()" must be a hash ref containing the parameters
       that describe the type and style of the data validation. The allowable parameters are:

           validate
           criteria
           value | minimum | source
           maximum
           ignore_blank
           dropdown

           input_title
           input_message
           show_input

           error_title
           error_message
           error_type
           show_error

       These parameters are explained in the following sections. Most of the parameters are
       optional, however, you will generally require the three main options "validate",
       "criteria" and "value".

           $worksheet->data_validation('B3',
               {
                   validate => 'integer',
                   criteria => '>',
                   value    => 100,
               });

       The "data_validation" method returns:

            0 for success.
           -1 for insufficient number of arguments.
           -2 for row or column out of bounds.
           -3 for incorrect parameter or value.

   validate
       This parameter is passed in a hash ref to "data_validation()".

       The "validate" parameter is used to set the type of data that you wish to validate. It is
       always required and it has no default value. Allowable values are:

           any
           integer
           decimal
           list
           date
           time
           length
           custom

       ·   any is used to specify that the type of data is unrestricted. This is the same as not
           applying a data validation. It is only provided for completeness and isn't used very
           often in the context of Spreadsheet::WriteExcel.

       ·   integer restricts the cell to integer values. Excel refers to this as 'whole number'.

               validate => 'integer',
               criteria => '>',
               value    => 100,

       ·   decimal restricts the cell to decimal values.

               validate => 'decimal',
               criteria => '>',
               value    => 38.6,

       ·   list restricts the cell to a set of user specified values. These can be passed in an
           array ref or as a cell range (named ranges aren't currently supported):

               validate => 'list',
               value    => ['open', 'high', 'close'],
               # Or like this:
               value    => 'B1:B3',

           Excel requires that range references are only to cells on the same worksheet.

       ·   date restricts the cell to date values. Dates in Excel are expressed as integer values
           but you can also pass an ISO860 style string as used in "write_date_time()". See also
           "DATES AND TIME IN EXCEL" for more information about working with Excel's dates.

               validate => 'date',
               criteria => '>',
               value    => 39653, # 24 July 2008
               # Or like this:
               value    => '2008-07-24T',

       ·   time restricts the cell to time values. Times in Excel are expressed as decimal values
           but you can also pass an ISO860 style string as used in "write_date_time()". See also
           "DATES AND TIME IN EXCEL" for more information about working with Excel's times.

               validate => 'time',
               criteria => '>',
               value    => 0.5, # Noon
               # Or like this:
               value    => 'T12:00:00',

       ·   length restricts the cell data based on an integer string length. Excel refers to this
           as 'Text length'.

               validate => 'length',
               criteria => '>',
               value    => 10,

       ·   custom restricts the cell based on an external Excel formula that returns a
           "TRUE/FALSE" value.

               validate => 'custom',
               value    => '=IF(A10>B10,TRUE,FALSE)',

   criteria
       This parameter is passed in a hash ref to "data_validation()".

       The "criteria" parameter is used to set the criteria by which the data in the cell is
       validated. It is almost always required except for the "list" and "custom" validate
       options. It has no default value. Allowable values are:

           'between'
           'not between'
           'equal to'                  |  '=='  |  '='
           'not equal to'              |  '!='  |  '<>'
           'greater than'              |  '>'
           'less than'                 |  '<'
           'greater than or equal to'  |  '>='
           'less than or equal to'     |  '<='

       You can either use Excel's textual description strings, in the first column above, or the
       more common operator alternatives. The following are equivalent:

           validate => 'integer',
           criteria => 'greater than',
           value    => 100,

           validate => 'integer',
           criteria => '>',
           value    => 100,

       The "list" and "custom" validate options don't require a "criteria". If you specify one it
       will be ignored.

           validate => 'list',
           value    => ['open', 'high', 'close'],

           validate => 'custom',
           value    => '=IF(A10>B10,TRUE,FALSE)',

   value | minimum | source
       This parameter is passed in a hash ref to "data_validation()".

       The "value" parameter is used to set the limiting value to which the "criteria" is
       applied. It is always required and it has no default value. You can also use the synonyms
       "minimum" or "source" to make the validation a little clearer and closer to Excel's
       description of the parameter:

           # Use 'value'
           validate => 'integer',
           criteria => '>',
           value    => 100,

           # Use 'minimum'
           validate => 'integer',
           criteria => 'between',
           minimum  => 1,
           maximum  => 100,

           # Use 'source'
           validate => 'list',
           source   => '$B$1:$B$3',

   maximum
       This parameter is passed in a hash ref to "data_validation()".

       The "maximum" parameter is used to set the upper limiting value when the "criteria" is
       either 'between' or 'not between':

           validate => 'integer',
           criteria => 'between',
           minimum  => 1,
           maximum  => 100,

   ignore_blank
       This parameter is passed in a hash ref to "data_validation()".

       The "ignore_blank" parameter is used to toggle on and off the 'Ignore blank' option in the
       Excel data validation dialog. When the option is on the data validation is not applied to
       blank data in the cell. It is on by default.

           ignore_blank => 0,  # Turn the option off

   dropdown
       This parameter is passed in a hash ref to "data_validation()".

       The "dropdown" parameter is used to toggle on and off the 'In-cell dropdown' option in the
       Excel data validation dialog. When the option is on a dropdown list will be shown for
       "list" validations. It is on by default.

           dropdown => 0,      # Turn the option off

   input_title
       This parameter is passed in a hash ref to "data_validation()".

       The "input_title" parameter is used to set the title of the input message that is
       displayed when a cell is entered. It has no default value and is only displayed if the
       input message is displayed. See the "input_message" parameter below.

           input_title   => 'This is the input title',

       The maximum title length is 32 characters. UTF8 strings are handled automatically in perl
       5.8 and later.

   input_message
       This parameter is passed in a hash ref to "data_validation()".

       The "input_message" parameter is used to set the input message that is displayed when a
       cell is entered. It has no default value.

           validate      => 'integer',
           criteria      => 'between',
           minimum       => 1,
           maximum       => 100,
           input_title   => 'Enter the applied discount:',
           input_message => 'between 1 and 100',

       The message can be split over several lines using newlines, "\n" in double quoted strings.

           input_message => "This is\na test.",

       The maximum message length is 255 characters. UTF8 strings are handled automatically in
       perl 5.8 and later.

   show_input
       This parameter is passed in a hash ref to "data_validation()".

       The "show_input" parameter is used to toggle on and off the 'Show input message when cell
       is selected' option in the Excel data validation dialog. When the option is off an input
       message is not displayed even if it has been set using "input_message". It is on by
       default.

           show_input => 0,      # Turn the option off

   error_title
       This parameter is passed in a hash ref to "data_validation()".

       The "error_title" parameter is used to set the title of the error message that is
       displayed when the data validation criteria is not met. The default error title is
       'Microsoft Excel'.

           error_title   => 'Input value is not valid',

       The maximum title length is 32 characters. UTF8 strings are handled automatically in perl
       5.8 and later.

   error_message
       This parameter is passed in a hash ref to "data_validation()".

       The "error_message" parameter is used to set the error message that is displayed when a
       cell is entered. The default error message is "The value you entered is not valid.\nA user
       has restricted values that can be entered into the cell.".

           validate      => 'integer',
           criteria      => 'between',
           minimum       => 1,
           maximum       => 100,
           error_title   => 'Input value is not valid',
           error_message => 'It should be an integer between 1 and 100',

       The message can be split over several lines using newlines, "\n" in double quoted strings.

           input_message => "This is\na test.",

       The maximum message length is 255 characters. UTF8 strings are handled automatically in
       perl 5.8 and later.

   error_type
       This parameter is passed in a hash ref to "data_validation()".

       The "error_type" parameter is used to specify the type of error dialog that is displayed.
       There are 3 options:

           'stop'
           'warning'
           'information'

       The default is 'stop'.

   show_error
       This parameter is passed in a hash ref to "data_validation()".

       The "show_error" parameter is used to toggle on and off the 'Show error alert after
       invalid data is entered' option in the Excel data validation dialog. When the option is
       off an error message is not displayed even if it has been set using "error_message". It is
       on by default.

           show_error => 0,      # Turn the option off

   Data Validation Examples
       Example 1. Limiting input to an integer greater than a fixed value.

           $worksheet->data_validation('A1',
               {
                   validate        => 'integer',
                   criteria        => '>',
                   value           => 0,
               });

       Example 2. Limiting input to an integer greater than a fixed value where the value is
       referenced from a cell.

           $worksheet->data_validation('A2',
               {
                   validate        => 'integer',
                   criteria        => '>',
                   value           => '=E3',
               });

       Example 3. Limiting input to a decimal in a fixed range.

           $worksheet->data_validation('A3',
               {
                   validate        => 'decimal',
                   criteria        => 'between',
                   minimum         => 0.1,
                   maximum         => 0.5,
               });

       Example 4. Limiting input to a value in a dropdown list.

           $worksheet->data_validation('A4',
               {
                   validate        => 'list',
                   source          => ['open', 'high', 'close'],
               });

       Example 5. Limiting input to a value in a dropdown list where the list is specified as a
       cell range.

           $worksheet->data_validation('A5',
               {
                   validate        => 'list',
                   source          => '=E4:G4',
               });

       Example 6. Limiting input to a date in a fixed range.

           $worksheet->data_validation('A6',
               {
                   validate        => 'date',
                   criteria        => 'between',
                   minimum         => '2008-01-01T',
                   maximum         => '2008-12-12T',
               });

       Example 7. Displaying a message when the cell is selected.

           $worksheet->data_validation('A7',
               {
                   validate      => 'integer',
                   criteria      => 'between',
                   minimum       => 1,
                   maximum       => 100,
                   input_title   => 'Enter an integer:',
                   input_message => 'between 1 and 100',
               });

       See also the "data_validate.pl" program in the examples directory of the distro.

ROW HEIGHTS AND WORKSHEET OBJECTS

       The following relates to worksheet objects such as images, comments and charts.

       If you specify the height of a row that contains a worksheet object then
       Spreadsheet::WriteExcel will adjust the height of the object to maintain its default or
       user specified dimensions. In this way the object won't appear stretched or compressed in
       Excel.

       However, Excel can also adjust the height of a row automatically if it contains cells that
       have the text wrap property set or contain large fonts. In these cases the height of the
       row is unknown to Spreadsheet::WriteExcel at execution time and the scaling calculations
       it performs are incorrect. The effect of this is that the  object is stretched with the
       row when it is displayed in Excel.

       In order to avoid this issue you should use the "set_row()" method to explicitly specify
       the height of any row that may otherwise be changed automatically by Excel.

FORMULAS AND FUNCTIONS IN EXCEL

   Caveats
       The first thing to note is that there are still some outstanding issues with the
       implementation of formulas and functions:

           1. Writing a formula is much slower than writing the equivalent string.
           2. You cannot use array constants, i.e. {1;2;3}, in functions.
           3. Unary minus isn't supported.
           4. Whitespace is not preserved around operators.
           5. Named ranges are not supported.
           6. Array formulas are not supported.

       However, these constraints will be removed in future versions. They are here because of a
       trade-off between features and time. Also, it is possible to work around issue 1 using the
       "store_formula()" and "repeat_formula()" methods as described later in this section.

   Introduction
       The following is a brief introduction to formulas and functions in Excel and
       Spreadsheet::WriteExcel.

       A formula is a string that begins with an equals sign:

           '=A1+B1'
           '=AVERAGE(1, 2, 3)'

       The formula can contain numbers, strings, boolean values, cell references, cell ranges and
       functions. Named ranges are not supported. Formulas should be written as they appear in
       Excel, that is cells and functions must be in uppercase.

       Cells in Excel are referenced using the A1 notation system where the column is designated
       by a letter and the row by a number. Columns range from A to IV i.e. 0 to 255, rows range
       from 1 to 65536. The "Spreadsheet::WriteExcel::Utility" module that is included in the
       distro contains helper functions for dealing with A1 notation, for example:

           use Spreadsheet::WriteExcel::Utility;

           ($row, $col) = xl_cell_to_rowcol('C2');  # (1, 2)
           $str         = xl_rowcol_to_cell(1, 2);  # C2

       The Excel "$" notation in cell references is also supported. This allows you to specify
       whether a row or column is relative or absolute. This only has an effect if the cell is
       copied. The following examples show relative and absolute values.

           '=A1'   # Column and row are relative
           '=$A1'  # Column is absolute and row is relative
           '=A$1'  # Column is relative and row is absolute
           '=$A$1' # Column and row are absolute

       Formulas can also refer to cells in other worksheets of the current workbook. For example:

           '=Sheet2!A1'
           '=Sheet2!A1:A5'
           '=Sheet2:Sheet3!A1'
           '=Sheet2:Sheet3!A1:A5'
           q{='Test Data'!A1}
           q{='Test Data1:Test Data2'!A1}

       The sheet reference and the cell reference are separated by  "!" the exclamation mark
       symbol. If worksheet names contain spaces, commas or parentheses then Excel requires that
       the name is enclosed in single quotes as shown in the last two examples above. In order to
       avoid using a lot of escape characters you can use the quote operator "q{}" to protect the
       quotes. See "perlop" in the main Perl documentation. Only valid sheet names that have been
       added using the "add_worksheet()" method can be used in formulas. You cannot reference
       external workbooks.

       The following table lists the operators that are available in Excel's formulas. The
       majority of the operators are the same as Perl's, differences are indicated:

           Arithmetic operators:
           =====================
           Operator  Meaning                   Example
              +      Addition                  1+2
              -      Subtraction               2-1
              *      Multiplication            2*3
              /      Division                  1/4
              ^      Exponentiation            2^3      # Equivalent to **
              -      Unary minus               -(1+2)   # Not yet supported
              %      Percent (Not modulus)     13%      # Not supported, [1]

           Comparison operators:
           =====================
           Operator  Meaning                   Example
               =     Equal to                  A1 =  B1 # Equivalent to ==
               <>    Not equal to              A1 <> B1 # Equivalent to !=
               >     Greater than              A1 >  B1
               <     Less than                 A1 <  B1
               >=    Greater than or equal to  A1 >= B1
               <=    Less than or equal to     A1 <= B1

           String operator:
           ================
           Operator  Meaning                   Example
               &     Concatenation             "Hello " & "World!" # [2]

           Reference operators:
           ====================
           Operator  Meaning                   Example
               :     Range operator            A1:A4               # [3]
               ,     Union operator            SUM(1, 2+2, B3)     # [4]

           Notes:
           [1]: You can get a percentage with formatting and modulus with MOD().
           [2]: Equivalent to ("Hello " . "World!") in Perl.
           [3]: This range is equivalent to cells A1, A2, A3 and A4.
           [4]: The comma behaves like the list separator in Perl.

       The range and comma operators can have different symbols in non-English versions of Excel.
       These will be supported in a later version of Spreadsheet::WriteExcel. European users of
       Excel take note:

           $worksheet->write('A1', '=SUM(1; 2; 3)'); # Wrong!!
           $worksheet->write('A1', '=SUM(1, 2, 3)'); # Okay

       The following table lists all of the core functions supported by Excel 5 and
       Spreadsheet::WriteExcel. Any additional functions that are available through the "Analysis
       ToolPak" or other add-ins are not supported. These functions have all been tested to
       verify that they work.

           ABS           DB            INDIRECT      NORMINV       SLN
           ACOS          DCOUNT        INFO          NORMSDIST     SLOPE
           ACOSH         DCOUNTA       INT           NORMSINV      SMALL
           ADDRESS       DDB           INTERCEPT     NOT           SQRT
           AND           DEGREES       IPMT          NOW           STANDARDIZE
           AREAS         DEVSQ         IRR           NPER          STDEV
           ASIN          DGET          ISBLANK       NPV           STDEVP
           ASINH         DMAX          ISERR         ODD           STEYX
           ATAN          DMIN          ISERROR       OFFSET        SUBSTITUTE
           ATAN2         DOLLAR        ISLOGICAL     OR            SUBTOTAL
           ATANH         DPRODUCT      ISNA          PEARSON       SUM
           AVEDEV        DSTDEV        ISNONTEXT     PERCENTILE    SUMIF
           AVERAGE       DSTDEVP       ISNUMBER      PERCENTRANK   SUMPRODUCT
           BETADIST      DSUM          ISREF         PERMUT        SUMSQ
           BETAINV       DVAR          ISTEXT        PI            SUMX2MY2
           BINOMDIST     DVARP         KURT          PMT           SUMX2PY2
           CALL          ERROR.TYPE    LARGE         POISSON       SUMXMY2
           CEILING       EVEN          LEFT          POWER         SYD
           CELL          EXACT         LEN           PPMT          T
           CHAR          EXP           LINEST        PROB          TAN
           CHIDIST       EXPONDIST     LN            PRODUCT       TANH
           CHIINV        FACT          LOG           PROPER        TDIST
           CHITEST       FALSE         LOG10         PV            TEXT
           CHOOSE        FDIST         LOGEST        QUARTILE      TIME
           CLEAN         FIND          LOGINV        RADIANS       TIMEVALUE
           CODE          FINV          LOGNORMDIST   RAND          TINV
           COLUMN        FISHER        LOOKUP        RANK          TODAY
           COLUMNS       FISHERINV     LOWER         RATE          TRANSPOSE
           COMBIN        FIXED         MATCH         REGISTER.ID   TREND
           CONCATENATE   FLOOR         MAX           REPLACE       TRIM
           CONFIDENCE    FORECAST      MDETERM       REPT          TRIMMEAN
           CORREL        FREQUENCY     MEDIAN        RIGHT         TRUE
           COS           FTEST         MID           ROMAN         TRUNC
           COSH          FV            MIN           ROUND         TTEST
           COUNT         GAMMADIST     MINUTE        ROUNDDOWN     TYPE
           COUNTA        GAMMAINV      MINVERSE      ROUNDUP       UPPER
           COUNTBLANK    GAMMALN       MIRR          ROW           VALUE
           COUNTIF       GEOMEAN       MMULT         ROWS          VAR
           COVAR         GROWTH        MOD           RSQ           VARP
           CRITBINOM     HARMEAN       MODE          SEARCH        VDB
           DATE          HLOOKUP       MONTH         SECOND        VLOOKUP
           DATEVALUE     HOUR          N             SIGN          WEEKDAY
           DAVERAGE      HYPGEOMDIST   NA            SIN           WEIBULL
           DAY           IF            NEGBINOMDIST  SINH          YEAR
           DAYS360       INDEX         NORMDIST      SKEW          ZTEST

       You can also modify the module to support function names in the following languages:
       German, French, Spanish, Portuguese, Dutch, Finnish, Italian and Swedish. See the
       "function_locale.pl" program in the "examples" directory of the distro.

       For a general introduction to Excel's formulas and an explanation of the syntax of the
       function refer to the Excel help files or the following:
       <http://office.microsoft.com/en-us/assistance/CH062528031033.aspx>.

       If your formula doesn't work in Spreadsheet::WriteExcel try the following:

           1. Verify that the formula works in Excel (or Gnumeric or OpenOffice.org).
           2. Ensure that it isn't on the Caveats list shown above.
           3. Ensure that cell references and formula names are in uppercase.
           4. Ensure that you are using ':' as the range operator, A1:A4.
           5. Ensure that you are using ',' as the union operator, SUM(1,2,3).
           6. Ensure that the function is in the above table.

       If you go through steps 1-6 and you still have a problem, mail me.

   Improving performance when working with formulas
       Writing a large number of formulas with Spreadsheet::WriteExcel can be slow. This is due
       to the fact that each formula has to be parsed and with the current implementation this is
       computationally expensive.

       However, in a lot of cases the formulas that you write will be quite similar, for example:

           $worksheet->write_formula('B1',    '=A1 * 3 + 50',    $format);
           $worksheet->write_formula('B2',    '=A2 * 3 + 50',    $format);
           ...
           ...
           $worksheet->write_formula('B99',   '=A999 * 3 + 50',  $format);
           $worksheet->write_formula('B1000', '=A1000 * 3 + 50', $format);

       In this example the cell reference changes in iterations from "A1" to "A1000". The parser
       treats this variable as a token and arranges it according to predefined rules. However,
       since the parser is oblivious to the value of the token, it is essentially performing the
       same calculation 1000 times. This is inefficient.

       The way to avoid this inefficiency and thereby speed up the writing of formulas is to
       parse the formula once and then repeatedly substitute similar tokens.

       A formula can be parsed and stored via the "store_formula()" worksheet method. You can
       then use the "repeat_formula()" method to substitute $pattern, $replace pairs in the
       stored formula:

           my $formula = $worksheet->store_formula('=A1 * 3 + 50');

           for my $row (0..999) {
               $worksheet->repeat_formula($row, 1, $formula, $format, 'A1', 'A'.($row +1));
           }

       On an arbitrary test machine this method was 10 times faster than the brute force method
       shown above.

       For more information about how Spreadsheet::WriteExcel parses and stores formulas see the
       "Spreadsheet::WriteExcel::Formula" man page.

       It should be noted however that the overall speed of direct formula parsing will be
       improved in a future version.

EXAMPLES

       See Spreadsheet::WriteExcel::Examples for a full list of examples.

   Example 1
       The following example shows some of the basic features of Spreadsheet::WriteExcel.

           #!/usr/bin/perl -w

           use strict;
           use Spreadsheet::WriteExcel;

           # Create a new workbook called simple.xls and add a worksheet
           my $workbook  = Spreadsheet::WriteExcel->new('simple.xls');
           my $worksheet = $workbook->add_worksheet();

           # The general syntax is write($row, $column, $token). Note that row and
           # column are zero indexed

           # Write some text
           $worksheet->write(0, 0,  'Hi Excel!');

           # Write some numbers
           $worksheet->write(2, 0,  3);          # Writes 3
           $worksheet->write(3, 0,  3.00000);    # Writes 3
           $worksheet->write(4, 0,  3.00001);    # Writes 3.00001
           $worksheet->write(5, 0,  3.14159);    # TeX revision no.?

           # Write some formulas
           $worksheet->write(7, 0,  '=A3 + A6');
           $worksheet->write(8, 0,  '=IF(A5>3,"Yes", "No")');

           # Write a hyperlink
           $worksheet->write(10, 0, 'http://www.perl.com/');

   Example 2
       The following is a general example which demonstrates some features of working with
       multiple worksheets.

           #!/usr/bin/perl -w

           use strict;
           use Spreadsheet::WriteExcel;

           # Create a new Excel workbook
           my $workbook = Spreadsheet::WriteExcel->new('regions.xls');

           # Add some worksheets
           my $north = $workbook->add_worksheet('North');
           my $south = $workbook->add_worksheet('South');
           my $east  = $workbook->add_worksheet('East');
           my $west  = $workbook->add_worksheet('West');

           # Add a Format
           my $format = $workbook->add_format();
           $format->set_bold();
           $format->set_color('blue');

           # Add a caption to each worksheet
           foreach my $worksheet ($workbook->sheets()) {
               $worksheet->write(0, 0, 'Sales', $format);
           }

           # Write some data
           $north->write(0, 1, 200000);
           $south->write(0, 1, 100000);
           $east->write (0, 1, 150000);
           $west->write (0, 1, 100000);

           # Set the active worksheet
           $south->activate();

           # Set the width of the first column
           $south->set_column(0, 0, 20);

           # Set the active cell
           $south->set_selection(0, 1);

   Example 3
       This example shows how to use a conditional numerical format with colours to indicate if a
       share price has gone up or down.

           use strict;
           use Spreadsheet::WriteExcel;

           # Create a new workbook and add a worksheet
           my $workbook  = Spreadsheet::WriteExcel->new('stocks.xls');
           my $worksheet = $workbook->add_worksheet();

           # Set the column width for columns 1, 2, 3 and 4
           $worksheet->set_column(0, 3, 15);

           # Create a format for the column headings
           my $header = $workbook->add_format();
           $header->set_bold();
           $header->set_size(12);
           $header->set_color('blue');

           # Create a format for the stock price
           my $f_price = $workbook->add_format();
           $f_price->set_align('left');
           $f_price->set_num_format('$0.00');

           # Create a format for the stock volume
           my $f_volume = $workbook->add_format();
           $f_volume->set_align('left');
           $f_volume->set_num_format('#,##0');

           # Create a format for the price change. This is an example of a
           # conditional format. The number is formatted as a percentage. If it is
           # positive it is formatted in green, if it is negative it is formatted
           # in red and if it is zero it is formatted as the default font colour
           # (in this case black). Note: the [Green] format produces an unappealing
           # lime green. Try [Color 10] instead for a dark green.
           #
           my $f_change = $workbook->add_format();
           $f_change->set_align('left');
           $f_change->set_num_format('[Green]0.0%;[Red]-0.0%;0.0%');

           # Write out the data
           $worksheet->write(0, 0, 'Company',$header);
           $worksheet->write(0, 1, 'Price',  $header);
           $worksheet->write(0, 2, 'Volume', $header);
           $worksheet->write(0, 3, 'Change', $header);

           $worksheet->write(1, 0, 'Damage Inc.'       );
           $worksheet->write(1, 1, 30.25,    $f_price ); # $30.25
           $worksheet->write(1, 2, 1234567,  $f_volume); # 1,234,567
           $worksheet->write(1, 3, 0.085,    $f_change); # 8.5% in green

           $worksheet->write(2, 0, 'Dump Corp.'        );
           $worksheet->write(2, 1, 1.56,     $f_price ); # $1.56
           $worksheet->write(2, 2, 7564,     $f_volume); # 7,564
           $worksheet->write(2, 3, -0.015,   $f_change); # -1.5% in red

           $worksheet->write(3, 0, 'Rev Ltd.'          );
           $worksheet->write(3, 1, 0.13,     $f_price ); # $0.13
           $worksheet->write(3, 2, 321,      $f_volume); # 321
           $worksheet->write(3, 3, 0,        $f_change); # 0 in the font color (black)

   Example 4
       The following is a simple example of using functions.

           #!/usr/bin/perl -w

           use strict;
           use Spreadsheet::WriteExcel;

           # Create a new workbook and add a worksheet
           my $workbook  = Spreadsheet::WriteExcel->new('stats.xls');
           my $worksheet = $workbook->add_worksheet('Test data');

           # Set the column width for columns 1
           $worksheet->set_column(0, 0, 20);

           # Create a format for the headings
           my $format = $workbook->add_format();
           $format->set_bold();

           # Write the sample data
           $worksheet->write(0, 0, 'Sample', $format);
           $worksheet->write(0, 1, 1);
           $worksheet->write(0, 2, 2);
           $worksheet->write(0, 3, 3);
           $worksheet->write(0, 4, 4);
           $worksheet->write(0, 5, 5);
           $worksheet->write(0, 6, 6);
           $worksheet->write(0, 7, 7);
           $worksheet->write(0, 8, 8);

           $worksheet->write(1, 0, 'Length', $format);
           $worksheet->write(1, 1, 25.4);
           $worksheet->write(1, 2, 25.4);
           $worksheet->write(1, 3, 24.8);
           $worksheet->write(1, 4, 25.0);
           $worksheet->write(1, 5, 25.3);
           $worksheet->write(1, 6, 24.9);
           $worksheet->write(1, 7, 25.2);
           $worksheet->write(1, 8, 24.8);

           # Write some statistical functions
           $worksheet->write(4,  0, 'Count', $format);
           $worksheet->write(4,  1, '=COUNT(B1:I1)');

           $worksheet->write(5,  0, 'Sum', $format);
           $worksheet->write(5,  1, '=SUM(B2:I2)');

           $worksheet->write(6,  0, 'Average', $format);
           $worksheet->write(6,  1, '=AVERAGE(B2:I2)');

           $worksheet->write(7,  0, 'Min', $format);
           $worksheet->write(7,  1, '=MIN(B2:I2)');

           $worksheet->write(8,  0, 'Max', $format);
           $worksheet->write(8,  1, '=MAX(B2:I2)');

           $worksheet->write(9,  0, 'Standard Deviation', $format);
           $worksheet->write(9,  1, '=STDEV(B2:I2)');

           $worksheet->write(10, 0, 'Kurtosis', $format);
           $worksheet->write(10, 1, '=KURT(B2:I2)');

   Example 5
       The following example converts a tab separated file called "tab.txt" into an Excel file
       called "tab.xls".

           #!/usr/bin/perl -w

           use strict;
           use Spreadsheet::WriteExcel;

           open (TABFILE, 'tab.txt') or die "tab.txt: $!";

           my $workbook  = Spreadsheet::WriteExcel->new('tab.xls');
           my $worksheet = $workbook->add_worksheet();

           # Row and column are zero indexed
           my $row = 0;

           while (<TABFILE>) {
               chomp;
               # Split on single tab
               my @Fld = split('\t', $_);

               my $col = 0;
               foreach my $token (@Fld) {
                   $worksheet->write($row, $col, $token);
                   $col++;
               }
               $row++;
           }

       NOTE: This is a simple conversion program for illustrative purposes only. For converting a
       CSV or Tab separated or any other type of delimited text file to Excel I recommend the
       more rigorous csv2xls program that is part of H.Merijn Brand's Text::CSV_XS module distro.

       See the examples/csv2xls link here:
       <http://search.cpan.org/~hmbrand/Text-CSV_XS/MANIFEST>.

   Additional Examples
       The following is a description of the example files that are provided in the standard
       Spreadsheet::WriteExcel distribution. They demonstrate the different features and options
       of the module.  See Spreadsheet::WriteExcel::Examples for more details.

           Getting started
           ===============
           a_simple.pl             A get started example with some basic features.
           demo.pl                 A demo of some of the available features.
           regions.pl              A simple example of multiple worksheets.
           stats.pl                Basic formulas and functions.
           formats.pl              All the available formatting on several worksheets.
           bug_report.pl           A template for submitting bug reports.

           Advanced
           ========
           autofilter.pl           Examples of worksheet autofilters.
           autofit.pl              Simulate Excel's autofit for column widths.
           bigfile.pl              Write past the 7MB limit with OLE::Storage_Lite.
           cgi.pl                  A simple CGI program.
           chart_area.pl           A demo of area style charts.
           chart_bar.pl            A demo of bar (vertical histogram) style charts.
           chart_column.pl         A demo of column (histogram) style charts.
           chart_line.pl           A demo of line style charts.
           chart_pie.pl            A demo of pie style charts.
           chart_scatter.pl        A demo of scatter style charts.
           chart_stock.pl          A demo of stock style charts.
           chess.pl                An example of reusing formatting via properties.
           colors.pl               A demo of the colour palette and named colours.
           comments1.pl            Add comments to worksheet cells.
           comments2.pl            Add comments with advanced options.
           copyformat.pl           Example of copying a cell format.
           data_validate.pl        An example of data validation and dropdown lists.
           date_time.pl            Write dates and times with write_date_time().
           defined_name.pl         Example of how to create defined names.
           diag_border.pl          A simple example of diagonal cell borders.
           easter_egg.pl           Expose the Excel97 flight simulator.
           filehandle.pl           Examples of working with filehandles.
           formula_result.pl       Formulas with user specified results.
           headers.pl              Examples of worksheet headers and footers.
           hide_sheet.pl           Simple example of hiding a worksheet.
           hyperlink1.pl           Shows how to create web hyperlinks.
           hyperlink2.pl           Examples of internal and external hyperlinks.
           images.pl               Adding images to worksheets.
           indent.pl               An example of cell indentation.
           merge1.pl               A simple example of cell merging.
           merge2.pl               A simple example of cell merging with formatting.
           merge3.pl               Add hyperlinks to merged cells.
           merge4.pl               An advanced example of merging with formatting.
           merge5.pl               An advanced example of merging with formatting.
           merge6.pl               An example of merging with Unicode strings.
           mod_perl1.pl            A simple mod_perl 1 program.
           mod_perl2.pl            A simple mod_perl 2 program.
           outline.pl              An example of outlines and grouping.
           outline_collapsed.pl    An example of collapsed outlines.
           panes.pl                An examples of how to create panes.
           properties.pl           Add document properties to a workbook.
           protection.pl           Example of cell locking and formula hiding.
           repeat.pl               Example of writing repeated formulas.
           right_to_left.pl        Change default sheet direction to right to left.
           row_wrap.pl             How to wrap data from one worksheet onto another.
           sales.pl                An example of a simple sales spreadsheet.
           sendmail.pl             Send an Excel email attachment using Mail::Sender.
           stats_ext.pl            Same as stats.pl with external references.
           stocks.pl               Demonstrates conditional formatting.
           tab_colors.pl           Example of how to set worksheet tab colours.
           textwrap.pl             Demonstrates text wrapping options.
           win32ole.pl             A sample Win32::OLE example for comparison.
           write_arrays.pl         Example of writing 1D or 2D arrays of data.
           write_handler1.pl       Example of extending the write() method. Step 1.
           write_handler2.pl       Example of extending the write() method. Step 2.
           write_handler3.pl       Example of extending the write() method. Step 3.
           write_handler4.pl       Example of extending the write() method. Step 4.
           write_to_scalar.pl      Example of writing an Excel file to a Perl scalar.

           Unicode
           =======
           unicode_utf16.pl        Simple example of using Unicode UTF16 strings.
           unicode_utf16_japan.pl  Write Japanese Unicode strings using UTF-16.
           unicode_cyrillic.pl     Write Russian Cyrillic strings using UTF-8.
           unicode_list.pl         List the chars in a Unicode font.
           unicode_2022_jp.pl      Japanese: ISO-2022-JP to utf8 in perl 5.8.
           unicode_8859_11.pl      Thai:     ISO-8859_11 to utf8 in perl 5.8.
           unicode_8859_7.pl       Greek:    ISO-8859_7  to utf8 in perl 5.8.
           unicode_big5.pl         Chinese:  BIG5        to utf8 in perl 5.8.
           unicode_cp1251.pl       Russian:  CP1251      to utf8 in perl 5.8.
           unicode_cp1256.pl       Arabic:   CP1256      to utf8 in perl 5.8.
           unicode_koi8r.pl        Russian:  KOI8-R      to utf8 in perl 5.8.
           unicode_polish_utf8.pl  Polish :  UTF8        to utf8 in perl 5.8.
           unicode_shift_jis.pl    Japanese: Shift JIS   to utf8 in perl 5.8.

           Utility
           =======
           csv2xls.pl              Program to convert a CSV file to an Excel file.
           tab2xls.pl              Program to convert a tab separated file to xls.
           datecalc1.pl            Convert Unix/Perl time to Excel time.
           datecalc2.pl            Calculate an Excel date using Date::Calc.
           lecxe.pl                Convert Excel to WriteExcel using Win32::OLE.

           Developer
           =========
           convertA1.pl            Helper functions for dealing with A1 notation.
           function_locale.pl      Add non-English function names to Formula.pm.
           writeA1.pl              Example of how to extend the module.

LIMITATIONS

       The following limits are imposed by Excel:

           Description                          Limit
           -----------------------------------  ------
           Maximum number of chars in a string  32767
           Maximum number of columns            256
           Maximum number of rows               65536
           Maximum chars in a sheet name        31
           Maximum chars in a header/footer     254

       For Excel 2007+ file limits see the Excel::Writer::XLSX module.

       The minimum file size is 6K due to the OLE overhead. The maximum file size is
       approximately 7MB (7087104 bytes) of BIFF data. This can be extended by installing
       Takanori Kawai's OLE::Storage_Lite module
       <http://search.cpan.org/search?dist=OLE-Storage_Lite> see the "bigfile.pl" example in the
       "examples" directory of the distro.

DOWNLOADING

       The latest version of this module is always available at:
       <http://search.cpan.org/search?dist=Spreadsheet-WriteExcel/>.

REQUIREMENTS

       This module requires Perl >= 5.005, Parse::RecDescent, File::Temp and OLE::Storage_Lite:

           http://search.cpan.org/search?dist=Parse-RecDescent/ # For formulas.
           http://search.cpan.org/search?dist=File-Temp/        # For set_tempdir().
           http://search.cpan.org/search?dist=OLE-Storage_Lite/ # For files > 7MB.

       Note, these aren't strict requirements. Spreadsheet::WriteExcel will work without these
       modules if you don't use write_formula(), set_tempdir() or create files greater than 7MB.
       However, it is best to install them if possible and they will be installed automatically
       if you use a tool such as CPAN.pm or ppm.

INSTALLATION

       See the INSTALL or install.html docs that come with the distribution or:
       <http://search.cpan.org/src/JMCNAMARA/Spreadsheet-WriteExcel-2.31/INSTALL>.

PORTABILITY

       Spreadsheet::WriteExcel will work on the majority of Windows, UNIX and Macintosh
       platforms. Specifically, the module will work on any system where perl packs floats in the
       64 bit IEEE format. The float must also be in little-endian format but it will be reversed
       if necessary. Thus:

           print join(' ', map { sprintf '%#02x', $_ } unpack('C*', pack 'd', 1.2345)), "\n";

       should give (or in reverse order):

           0x8d 0x97 0x6e 0x12 0x83 0xc0 0xf3 0x3f

       In general, if you don't know whether your system supports a 64 bit IEEE float or not, it
       probably does. If your system doesn't, WriteExcel will "croak()" with the message given in
       the "DIAGNOSTICS" section. You can check which platforms the module has been tested on at
       the CPAN testers site:
       <http://testers.cpan.org/search?request=dist&dist=Spreadsheet-WriteExcel>.

DIAGNOSTICS

       Filename required by Spreadsheet::WriteExcel->new()
           A filename must be given in the constructor.

       Can't open filename. It may be in use or protected.
           The file cannot be opened for writing. The directory that you are writing to  may be
           protected or the file may be in use by another program.

       Unable to create tmp files via File::Temp::tempfile()...
           This is a "-w" warning. You will see it if you are using Spreadsheet::WriteExcel in an
           environment where temporary files cannot be created, in which case all data will be
           stored in memory. The warning is for information only: it does not affect creation but
           it will affect the speed of execution for large files. See the "set_tempdir" workbook
           method.

       Maximum file size, 7087104, exceeded.
           The current OLE implementation only supports a maximum BIFF file of this size. This
           limit can be extended, see the "LIMITATIONS" section.

       Can't locate Parse/RecDescent.pm in @INC ...
           Spreadsheet::WriteExcel requires the Parse::RecDescent module. Download it from CPAN:
           <http://search.cpan.org/search?dist=Parse-RecDescent>

       Couldn't parse formula ...
           There are a large number of warnings which relate to badly formed formulas and
           functions. See the "FORMULAS AND FUNCTIONS IN EXCEL" section for suggestions on how to
           avoid these errors. You should also check the formula in Excel to ensure that it is
           valid.

       Required floating point format not supported on this platform.
           Operating system doesn't support 64 bit IEEE float or it is byte-ordered in a way
           unknown to WriteExcel.

       'file.xls' cannot be accessed. The file may be read-only ...
           You may sometimes encounter the following error when trying to open a file in Excel:
           "file.xls cannot be accessed. The file may be read-only, or you may be trying to
           access a read-only location. Or, the server the document is stored on may not be
           responding."

           This error generally means that the Excel file has been corrupted. There are two
           likely causes of this: the file was FTPed in ASCII mode instead of binary mode or else
           the file was created with "UTF-8" data returned by an XML parser. See "Warning about
           XML::Parser and perl 5.6" for further details.

THE EXCEL BINARY FORMAT

       The following is some general information about the Excel binary format for anyone who may
       be interested.

       Excel data is stored in the "Binary Interchange File Format" (BIFF) file format. Details
       of this format are given in "Excel 97-2007 Binary File Format Specification"
       <http://www.microsoft.com/interop/docs/OfficeBinaryFormats.mspx>.

       Daniel Rentz of OpenOffice.org has also written a detailed description of the Excel
       workbook records, see <http://sc.openoffice.org/excelfileformat.pdf>.

       Charles Wybble has collected together additional information about the Excel file format.
       See "The Chicago Project" at <http://chicago.sourceforge.net/devel/>.

       The BIFF data is stored along with other data in an OLE Compound File. This is a
       structured storage which acts like a file system within a file. A Compound File is
       comprised of storages and streams which, to follow the file system analogy, are like
       directories and files.

       The OLE format is explained in the "Windows Compound Binary File Format Specification"
       <http://www.microsoft.com/interop/docs/supportingtechnologies.mspx>

       The Digital Imaging Group have also detailed the OLE format in the JPEG2000 specification:
       see Appendix A of <http://www.i3a.org/pdf/wg1n1017.pdf>.

       Please note that the provision of this information does not constitute an invitation to
       start hacking at the BIFF or OLE file formats. There are more interesting ways to waste
       your time. ;-)

WRITING EXCEL FILES

       Depending on your requirements, background and general sensibilities you may prefer one of
       the following methods of getting data into Excel:

       ·   Win32::OLE module and office automation

           This requires a Windows platform and an installed copy of Excel. This is the most
           powerful and complete method for interfacing with Excel. See
           <http://www.activestate.com/ASPN/Reference/Products/ActivePerl-5.6/faq/Windows/ActivePerl-Winfaq12.html>
           and
           <http://www.activestate.com/ASPN/Reference/Products/ActivePerl-5.6/site/lib/Win32/OLE.html>.
           If your main platform is UNIX but you have the resources to set up a separate
           Win32/MSOffice server, you can convert office documents to text, postscript or PDF
           using Win32::OLE. For a demonstration of how to do this using Perl see Docserver:
           <http://search.cpan.org/search?mode=module&query=docserver>.

       ·   CSV, comma separated variables or text

           If the file extension is "csv", Excel will open and convert this format automatically.
           Generating a valid CSV file isn't as easy as it seems. Have a look at the DBD::RAM,
           DBD::CSV, Text::xSV and Text::CSV_XS modules.

       ·   DBI with DBD::ADO or DBD::ODBC

           Excel files contain an internal index table that allows them to act like a database
           file. Using one of the standard Perl database modules you can connect to an Excel file
           as a database.

       ·   DBD::Excel

           You can also access Spreadsheet::WriteExcel using the standard DBI interface via
           Takanori Kawai's DBD::Excel module <http://search.cpan.org/dist/DBD-Excel>

       ·   Spreadsheet::WriteExcelXML

           This module allows you to create an Excel XML file using the same interface as
           Spreadsheet::WriteExcel. See: <http://search.cpan.org/dist/Spreadsheet-WriteExcelXML>

       ·   Excel::Template

           This module allows you to create an Excel file from an XML template in a manner
           similar to HTML::Template. See <http://search.cpan.org/dist/Excel-Template/>.

       ·   Spreadsheet::WriteExcel::FromXML

           This module allows you to turn a simple XML file into an Excel file using
           Spreadsheet::WriteExcel as a back-end. The format of the XML file is defined by a
           supplied DTD: <http://search.cpan.org/dist/Spreadsheet-WriteExcel-FromXML>.

       ·   Spreadsheet::WriteExcel::Simple

           This provides an easier interface to Spreadsheet::WriteExcel:
           <http://search.cpan.org/dist/Spreadsheet-WriteExcel-Simple>.

       ·   Spreadsheet::WriteExcel::FromDB

           This is a useful module for creating Excel files directly from a DB table:
           <http://search.cpan.org/dist/Spreadsheet-WriteExcel-FromDB>.

       ·   HTML tables

           This is an easy way of adding formatting via a text based format.

       ·   XML or HTML

           The Excel XML and HTML file specification are available from
           <http://msdn.microsoft.com/library/officedev/ofxml2k/ofxml2k.htm>.

       For other Perl-Excel modules try the following search:
       <http://search.cpan.org/search?mode=module&query=excel>.

READING EXCEL FILES

       To read data from Excel files try:

       ·   Spreadsheet::ParseExcel

           This uses the OLE::Storage-Lite module to extract data from an Excel file.
           <http://search.cpan.org/dist/Spreadsheet-ParseExcel>.

       ·   Spreadsheet::ParseExcel_XLHTML

           This module uses Spreadsheet::ParseExcel's interface but uses xlHtml (see below) to do
           the conversion: <http://search.cpan.org/dist/Spreadsheet-ParseExcel_XLHTML>
           Spreadsheet::ParseExcel_XLHTML

       ·   xlHtml

           This is an open source "Excel to HTML Converter" C/C++ project at
           <http://chicago.sourceforge.net/xlhtml/>.

       ·   DBD::Excel (reading)

           You can also access Spreadsheet::ParseExcel using the standard DBI interface via
           Takanori Kawai's DBD::Excel module <http://search.cpan.org/dist/DBD-Excel>.

       ·   Win32::OLE module and office automation (reading)

           See, the section "WRITING EXCEL FILES".

       ·   HTML tables (reading)

           If the files are saved from Excel in a HTML format the data can be accessed using
           HTML::TableExtract <http://search.cpan.org/dist/HTML-TableExtract>.

       ·   DBI with DBD::ADO or DBD::ODBC.

           See, the section "WRITING EXCEL FILES".

       ·   XML::Excel

           Converts Excel files to XML using Spreadsheet::ParseExcel
           <http://search.cpan.org/dist/XML-Excel>.

       ·   OLE::Storage, aka LAOLA

           This is a Perl interface to OLE file formats. In particular, the distro contains an
           Excel to HTML converter called Herbert, <http://user.cs.tu-berlin.de/~schwartz/pmh/>.
           This has been superseded by the Spreadsheet::ParseExcel module.

       For other Perl-Excel modules try the following search:
       <http://search.cpan.org/search?mode=module&query=excel>.

       If you wish to view Excel files on a UNIX/Linux platform check out the excellent Gnumeric
       spreadsheet application at <http://www.gnome.org/projects/gnumeric/> or OpenOffice.org at
       <http://www.openoffice.org/>.

       If you wish to view Excel files on a Windows platform which doesn't have Excel installed
       you can use the free Microsoft Excel Viewer
       <http://office.microsoft.com/downloads/2000/xlviewer.aspx>.

MODIFYING AND REWRITING EXCEL FILES

       An Excel file is a binary file within a binary file. It contains several interlinked
       checksums and changing even one byte can cause it to become corrupted.

       As such you cannot simply append or update an Excel file. The only way to achieve this is
       to read the entire file into memory, make the required changes or additions and then write
       the file out again.

       You can read and rewrite an Excel file using the Spreadsheet::ParseExcel::SaveParser
       module which is a wrapper around Spreadsheet::ParseExcel and Spreadsheet::WriteExcel. It
       is part of the Spreadsheet::ParseExcel package:
       <http://search.cpan.org/search?dist=Spreadsheet-ParseExcel>.

       However, you can only rewrite the features that Spreadsheet::WriteExcel supports so
       macros, graphs and some other features in the original Excel file will be lost. Also,
       formulas aren't rewritten, only the result of a formula is written.

       Here is an example:

           #!/usr/bin/perl -w

           use strict;
           use Spreadsheet::ParseExcel;
           use Spreadsheet::ParseExcel::SaveParser;

           # Open the template with SaveParser
           my $parser   = new Spreadsheet::ParseExcel::SaveParser;
           my $template = $parser->Parse('template.xls');

           my $sheet    = 0;
           my $row      = 0;
           my $col      = 0;

           # Get the format from the cell
           my $format   = $template->{Worksheet}[$sheet]
                                   ->{Cells}[$row][$col]
                                   ->{FormatNo};

           # Write data to some cells
           $template->AddCell(0, $row,   $col,   1,     $format);
           $template->AddCell(0, $row+1, $col, "Hello", $format);

           # Add a new worksheet
           $template->AddWorksheet('New Data');

           # The SaveParser SaveAs() method returns a reference to a
           # Spreadsheet::WriteExcel object. If you wish you can then
           # use this to access any of the methods that aren't
           # available from the SaveParser object. If you don't need
           # to do this just use SaveAs().
           #
           my $workbook;

           {
               # SaveAs generates a lot of harmless warnings about unset
               # Worksheet properties. You can ignore them if you wish.
               local $^W = 0;

               # Rewrite the file or save as a new file
               $workbook = $template->SaveAs('new.xls');
           }

           # Use Spreadsheet::WriteExcel methods
           my $worksheet  = $workbook->sheets(0);

           $worksheet->write($row+2, $col, "World2");

           $workbook->close();

Warning about XML::Parser and perl 5.6

       You must be careful when using Spreadsheet::WriteExcel in conjunction with perl 5.6 and
       XML::Parser (and other XML parsers) due to the fact that the data returned by the parser
       is generally in "UTF-8" format.

       When "UTF-8" strings are added to Spreadsheet::WriteExcel's internal data it causes the
       generated Excel file to become corrupt.

       Note, this doesn't affect perl 5.005 (which doesn't try to handle "UTF-8") or 5.8 (which
       handles it correctly).

       To avoid this problem you should upgrade to perl 5.8, if possible, or else you should
       convert the output data from XML::Parser to ASCII or ISO-8859-1 using one of the following
       methods:

           $new_str = pack 'C*', unpack 'U*', $utf8_str;

           use Unicode::MapUTF8 'from_utf8';
           $new_str = from_utf8({-str => $utf8_str, -charset => 'ISO-8859-1'});

Warning about Office Service Pack 3

       If you have Office Service Pack 3 (SP3) installed you may see the following warning when
       you open a file created by Spreadsheet::WriteExcel:

           "File Error: data may have been lost".

       This is usually caused by multiple instances of data in a cell.

       SP3 changed Excel's default behaviour when it encounters multiple data in a cell so that
       it issues a warning when the file is opened and it displays the first data that was
       written. Prior to SP3 it didn't issue a warning and displayed the last data written.

       For a longer discussion and some workarounds see the following:
       <http://groups.google.com/group/spreadsheet-writeexcel/browse_thread/thread/3dcea40e6620af3a>.

BUGS

       Formulas are formulae.

       XML and "UTF-8" data on perl 5.6 can cause Excel files created by Spreadsheet::WriteExcel
       to become corrupt. See "Warning about XML::Parser and perl 5.6" for further details.

       The format object that is used with a "merge_range()" method call is marked internally as
       being associated with a merged range. It is a fatal error to use a merged format in a non-
       merged cell. The current workaround is to use separate formats for merged and non-merged
       cell. This restriction will be removed in a future release.

       Nested formulas sometimes aren't parsed correctly and give a result of "#VALUE". If you
       come across a formula that parses like this, let me know.

       Spreadsheet::ParseExcel: All formulas created by Spreadsheet::WriteExcel are read as
       having a value of zero. This is because Spreadsheet::WriteExcel only stores the formula
       and not the calculated result.

       OpenOffice.org: No known issues in this release.

       Gnumeric: No known issues in this release.

       If you wish to submit a bug report run the "bug_report.pl" program in the "examples"
       directory of the distro.

Migrating to Excel::Writer::XLSX

       Spreadsheet::WriteExcel is in maintenance only mode and has effectively been superseded by
       Excel::Writer::XLSX.

       Excel::Writer::XLSX is an API compatible, drop-in replacement for Spreadsheet::WriteExcel.
       It also has many more features such as conditional formats, better charts, better formula
       handling, Excel tables and even sparklines.

       To convert your Spreadsheet::WriteExcel program to Excel::Writer::XLSX you only need do
       the following:

       ·   Substitute Excel::Writer::XLSX for Spreadsheet::WriteExcel in your program.

       ·   Change the file extension of the output file from ".xls" to ".xlsx".

       ·   Optionally replace "store_formula()" and "repeat_formula()" with "write_formula()"
           which is no longer an expensive operation in Excel::Writer::XLSX. However, you can
           leave them unchanged if required.

       There are some differences between the formats and the modules that are worth noting:

       ·   The default font in the XLSX format is Calibri 11 not Arial 10.

       ·   Default column widths and row heights are different between XLS and XLSX.

       ·   The Excel::Writer::XLSX module uses more memory by default but has a optimisation mode
           to reduce usage for large files.

       ·   The XLSX format doesn't have reading support that is as complete as
           Spreadsheet::ParseExcel.

REPOSITORY

       The Spreadsheet::WriteExcel source code in host on github:
       <http://github.com/jmcnamara/spreadsheet-writeexcel>.

MAILING LIST

       There is a Google group for discussing and asking questions about Spreadsheet::WriteExcel.
       This is a good place to search to see if your question has been asked before:
       <http://groups.google.com/group/spreadsheet-writeexcel>.

       Alternatively you can keep up to date with future releases by subscribing at:
       <http://freshmeat.net/projects/writeexcel/>.

DONATIONS

       If you'd care to donate to the Spreadsheet::WriteExcel project, you can do so via PayPal:
       <http://tinyurl.com/7ayes>.

SEE ALSO

       Spreadsheet::ParseExcel: <http://search.cpan.org/dist/Spreadsheet-ParseExcel>.

       Spreadsheet-WriteExcel-FromXML:
       <http://search.cpan.org/dist/Spreadsheet-WriteExcel-FromXML>.

       Spreadsheet::WriteExcel::FromDB:
       <http://search.cpan.org/dist/Spreadsheet-WriteExcel-FromDB>.

       Excel::Template: <http://search.cpan.org/~rkinyon/Excel-Template/>.

       DateTime::Format::Excel: <http://search.cpan.org/dist/DateTime-Format-Excel>.

       "Reading and writing Excel files with Perl" by Teodor Zlatanov, at IBM developerWorks:
       <http://www-106.ibm.com/developerworks/library/l-pexcel/>.

       "Excel-Dateien mit Perl erstellen - Controller im Gluck" by Peter Dintelmann and Christian
       Kirsch in the German Unix/web journal iX: <http://www.heise.de/ix/artikel/2001/06/175/>.

       Spreadsheet::WriteExcel documentation in Japanese by Takanori Kawai.
       <http://member.nifty.ne.jp/hippo2000/perltips/Spreadsheet/WriteExcel.htm>.

       Oesterly user brushes with fame: <http://oesterly.com/releases/12102000.html>.

       The csv2xls program that is part of Text::CSV_XS:
       <http://search.cpan.org/~hmbrand/Text-CSV_XS/MANIFEST>.

ACKNOWLEDGMENTS

       The following people contributed to the debugging and testing of Spreadsheet::WriteExcel:

       Alexander Farber, Andre de Bruin, Arthur@ais, Artur Silveira da Cunha, Bob Rose, Borgar
       Olsen, Brian Foley, Brian White, Bob Mackay, Cedric Bouvier, Chad Johnson, CPAN testers,
       Damyan Ivanov, Daniel Berger, Daniel Gardner, Dmitry Kochurov, Eric Frazier, Ernesto
       Baschny, Felipe Perez Galiana, Gordon Simpson, Hanc Pavel, Harold Bamford, James Holmes,
       James Wilkinson, Johan Ekenberg, Johann Hanne, Jonathan Scott Duff, J.C. Wren, Kenneth
       Stacey, Keith Miller, Kyle Krom, Marc Rosenthal, Markus Schmitz, Michael Braig, Michael
       Buschauer, Mike Blazer, Michael Erickson, Michael W J West, Ning Xie, Paul J. Falbe, Paul
       Medynski, Peter Dintelmann, Pierre Laplante, Praveen Kotha, Reto Badertscher, Rich Sorden,
       Shane Ashby, Sharron McKenzie, Shenyu Zheng, Stephan Loescher, Steve Sapovits, Sven
       Passig, Svetoslav Marinov, Tamas Gulacsi, Troy Daniels, Vahe Sarkissian.

       The following people contributed patches, examples or Excel information:

       Andrew Benham, Bill Young, Cedric Bouvier, Charles Wybble, Daniel Rentz, David Robins,
       Franco Venturi, Guy Albertelli, Ian Penman, John Heitmann, Jon Guy, Kyle R. Burton,
       Pierre-Jean Vouette, Rubio, Marco Geri, Mark Fowler, Matisse Enzer, Sam Kington, Takanori
       Kawai, Tom O'Sullivan.

       Many thanks to Ron McKelvey, Ronzo Consulting for Siemens, who sponsored the development
       of the formula caching routines.

       Many thanks to Cassens Transport who sponsored the development of the embedded charts and
       autofilters.

       Additional thanks to Takanori Kawai for translating the documentation into Japanese.

       Gunnar Wolf maintains the Debian distro.

       Thanks to Damian Conway for the excellent Parse::RecDescent.

       Thanks to Tim Jenness for File::Temp.

       Thanks to Michael Meeks and Jody Goldberg for their work on Gnumeric.

DISCLAIMER OF WARRANTY

       Because this software is licensed free of charge, there is no warranty for the software,
       to the extent permitted by applicable law. Except when otherwise stated in writing the
       copyright holders and/or other parties provide the software "as is" without warranty of
       any kind, either expressed or implied, including, but not limited to, the implied
       warranties of merchantability and fitness for a particular purpose. The entire risk as to
       the quality and performance of the software is with you. Should the software prove
       defective, you assume the cost of all necessary servicing, repair, or correction.

       In no event unless required by applicable law or agreed to in writing will any copyright
       holder, or any other party who may modify and/or redistribute the software as permitted by
       the above licence, be liable to you for damages, including any general, special,
       incidental, or consequential damages arising out of the use or inability to use the
       software (including but not limited to loss of data or data being rendered inaccurate or
       losses sustained by you or third parties or a failure of the software to operate with any
       other software), even if such holder or other party has been advised of the possibility of
       such damages.

LICENSE

       Either the Perl Artistic Licence <http://dev.perl.org/licenses/artistic.html> or the GPL
       <http://www.opensource.org/licenses/gpl-license.php>.

AUTHOR

       John McNamara jmcnamara@cpan.org

           The ashtray says
           You were up all night.
           When you went to bed
           With your darkest mind.
           Your pillow wept
           And covered your eyes.
           And you finally slept
           While the sun caught fire.

           You've changed.
             -- Jeff Tweedy

COPYRIGHT

       Copyright MM-MMXII, John McNamara.

       All Rights Reserved. This module is free software. It may be used, redistributed and/or
       modified under the same terms as Perl itself.