NAME

       Ifeffit - Perl interface to the IFEFFIT XAFS Analysis library.

SYNOPSIS

           use Ifeffit;
           use Ifeffit qw(put_scalar put_string put_array);
           use Ifeffit qw(get_scalar get_string get_array);

           my ($kmin, $my_file, $file_type ) = (0.01, "Cu.xmu", "xmu");
           put_scalar("rbkg", 1.1);
           put_scalar("kmin", $kmin);
           put_string("filename", $my_file);

           ifeffit(" read_data($my_file, prefix= my,");
           ifeffit("           type= $file_type)");
           ifeffit(" newplot (energy, xmu ) ");

           my $e0 = get_scalar("e0");
           print "e0 = $e0 , rbkg  = " ,get_scalar("rbkg"), "\n";

DESCRIPTION

       The Ifeffit Perl Module gives access to the ifeffit library for XAFS analysis.  The module
       provides seven perl functions - ifeffit, put_scalar, get_scalar, put_string, get_string,
       put_array, and get_array.  The ifeffit is always provided (ie, exported by the "use
       Ifeffit;" pragma), but the other commands must be explicitly imported, as shown above.

   ifeffit
       The ifeffit function provides the main interface to the ifeffit engine.  The character
       string argument is interpreted as an ifeffit command.  Ifeffit returns 0 if a valid
       command is sent and fully processed, -1 if a partial command has been sent (so that it
       will be expecting the rest of the command next), 1 if the "quit" command has been sent,
       and other non-zero valuses on error.  The syntax for and meaning of command lines to
       ifeffit is described in The Ifeffit Reference Manual of the Ifeffit distribution.  The
       syntax for the perl function is

       "$i = ifeffit("plot(my.x,  my.y)");"

   put_scalar
       This sets the value of a named scalar in the list of ifeffit data.  The set value is
       returned on successful execution.  The syntax is

       "$i = put_scalar("kweight", 2.0);".

       which is equivalent to

       "$i = ifeffit("kweight = 2.0");"

       But having a choice seems like the perl way.

   get_scalar
       This returns the value of a named ifeffit scalar. The syntax is

       "$value = get_scalar("x");"

   put_string
       This sets the value of a named ifeffit string.  The value is returned on successful
       execution.  The syntax is

       "$i = put_text("home", "the merry old land of oz");".

       The same effect could be achieved with the command

       "$i = ifeffit("set \$home = 'the merry old land of oz'");".

       but put_text takes care of the icky leading dollar sign, and returns the string instead of
       a simple exit status.

   get_string
       This returns the value of a named ifeffit string.  The syntax is

       "$bg = get_string("plot_bg");"

   put_array
       This copies a perl array of numeric values to an ifeffit array.  The syntax is

       "put_array("my.array",\@array);"

       which creates (or overwrites) the ifeffit array my.array, and fill it with the values of
       the perl array @array.  Note that the reference to the array is passed into put_array, not
       the whole array itself!

   get_array
       This gets the values of an ifeffit array of numeric values. The syntax is

       "@array = get_array("my.array");"

       which will fill the perl array @array with the ifeffit array my.array.

REVISION HISTORY

       1.3 Begin distributing with horae package.

       1.3 (1)
           Force enclosure of string by double quotes in the put_string function.  (Bruce Ravel
           18 Feb. 2003)

AUTHOR

       Matthew Newville  --  newville@cars.uchicago.edu

SEE ALSO

       ifeffit, Ifeffit Reference Manual, perl(1)

       PGPERL, PDL,  GNU ReadLine Library