Ubuntu Manpage: stilts-tcat - Concatenates multiple similar tables

NAME

       stilts-tcat - Concatenates multiple similar tables

SYNOPSIS

       stilts tcat [in=<table> [<table> ...]] [ifmt=<in-format>] [multi=true|false]
                   [istream=true|false] [icmd=<cmds>] [ocmd=<cmds>]
                   [omode=out|meta|stats|count|cgi|discard|topcat|samp|tosql|gui] [out=<out-
                   table>] [ofmt=<out-format>] [seqcol=<colname>] [loccol=<colname>]
                   [uloccol=<colname>] [lazy=true|false] [countrows=true|false]

DESCRIPTION

       tcat  is  a  tool  for concatenating any number of similar tables one after the other. The
       tables must be of similar  form  to  each  other  (same  number  and  types  of  columns).
       Preprocessing  of  the  tables may be done using the icmd parameter, which will operate in
       the same way on all the input tables. Table parameters of the output table will  be  taken
       from the first of the input tables.

       Subject to some constraints on the details of the input and output formats and processing,
       tcat is capable of joining an unlimited number of tables together  to  produce  an  output
       table of unlimited length, without large memory requirements.

       If   you   have   heterogeneous  tables,  in  different  formats  or  requiring  different
       preprocessing steps from each other before they can be concatenated, use tcatn instead.

OPTIONS

in=<table> [<table> ...]
Locations of the input tables. Either specify the parameter multiple times, or
supply the input tables as a space-separated list within a single use.

The following table location forms are allowed:

* A filename.

* A URL.

* The special value "-", meaning standard input. In this case the input format
must be given explicitly using the ifmt parameter. Note that not all formats
can be streamed in this way.

* A system command line with either a "<" character at the start, or a "|"
character at the end ("<syscmd" or "syscmd|"). This executes the given pipeline
and reads from its standard output. This will probably only work on unix-like
systems.
Compression in any of the supported compression formats (Unix compress, gzip or
bzip2) is expanded automatically.

A list of input table locations may be given in an external file by using the
indirction character '@'. Thus "in=@filename" causes the file filename to be read
for a list of input table locations. The locations in the file should each be on a
separate line.

ifmt=<in-format>
Specifies the format of the input table as specified by parameter in. The known
formats are listed in SUN/256. This flag can be used if you know what format your
table is in. If it has the special value (auto) (the default), then an attempt will
be made to detect the format of the table automatically. This cannot always be done
correctly however, in which case the program will exit with an error explaining
which formats were attempted.

The same format parameter applies to all the tables specified by in.

multi=true|false
Determines whether all tables, or just the first one, from input table files will
be used. If set false, then just the first table from each file named by in will be
used. If true, then all tables present in those input files will be used. This only
has an effect for file formats which are capable of containing more than one table,
which effectively means FITS and VOTable and their variants.

istream=true|false
If set true, the input table specified by the in parameter will be read as a
stream. It is necessary to give the ifmt parameter in this case. Depending on the
required operations and processing mode, this may cause the read to fail (sometimes
it is necessary to read the table more than once). It is not normally necessary to
set this flag; in most cases the data will be streamed automatically if that is the
best thing to do. However it can sometimes result in less resource usage when
processing large files in certain formats (such as VOTable).

The same streaming flag applies to all the tables specified by in.

icmd=<cmds>
Specifies processing to be performed on each input table as specified by parameter
in, before any other processing has taken place. The value of this parameter is one
or more of the filter commands described in SUN/256. If more than one is given,
they must be separated by semicolon characters (";"). This parameter can be
repeated multiple times on the same command line to build up a list of processing
steps. The sequence of commands given in this way defines the processing pipeline
which is performed on the table.

Commands may alteratively be supplied in an external file, by using the indirection
character '@'. Thus a value of "@filename" causes the file filename to be read for
a list of filter commands to execute. The commands in the file may be separated by
newline characters and/or semicolons, and lines which are blank or which start with
a '#' character are ignored.

ocmd=<cmds>
Specifies processing to be performed on the output table, after all other
processing has taken place. The value of this parameter is one or more of the
filter commands described in SUN/256. If more than one is given, they must be
separated by semicolon characters (";"). This parameter can be repeated multiple
times on the same command line to build up a list of processing steps. The sequence
of commands given in this way defines the processing pipeline which is performed on
the table.

omode=out|meta|stats|count|cgi|discard|topcat|samp|tosql|gui
The mode in which the result table will be output. The default mode is out, which
means that the result will be written as a new table to disk or elsewhere, as
determined by the out and ofmt parameters. However, there are other possibilities,
which correspond to uses to which a table can be put other than outputting it, such
as displaying metadata, calculating statistics, or populating a table in an SQL
database. For some values of this parameter, additional parameters (<mode-args>)
are required to determine the exact behaviour.

Possible values are

* out

* meta

* stats

* count

* cgi

* discard

* topcat

* samp

* tosql

* gui
Use the help=omode flag or see SUN/256 for more information.

out=<out-table>
The location of the output table. This is usually a filename to write to. If it is
equal to the special value "-" (the default) the output table will be written to
standard output.

This parameter must only be given if omode has its default value of "out".

ofmt=<out-format>
Specifies the format in which the output table will be written (one of the ones in
SUN/256 - matching is case-insensitive and you can use just the first few letters).
If it has the special value "(auto)" (the default), then the output filename will
be examined to try to guess what sort of file is required usually by looking at the
extension. If it's not obvious from the filename what output format is intended, an
error will result.

This parameter must only be given if omode has its default value of "out".

seqcol=<colname>
Name of a column to be added to the output table which will contain the sequence
number of the input table from which each row originated. This column will contain
1 for the rows from the first concatenated table, 2 for the second, and so on.

loccol=<colname>
Name of a column to be added to the output table which will contain the location
(as specified in the input parameter(s)) of the input table from which each row
originated.

uloccol=<colname>
Name of a column to be added to the output table which will contain the unique part
of the location (as specified in the input parameter(s)) of the input table from
which each row originated. If not null, parameters will also be added to the output
table giving the pre- and post-fix string common to all the locations. For example,
if the input tables are "/data/cat_a1.fits" and "/data/cat_b2.fits" then the output
table will contain a new column <colname> which takes the value "a1" for rows from
the first table and "b2" for rows from the second, and new parameters
"<colname>_prefix" and "<colname>_postfix" with the values "/data/cat_" and ".fits"
respectively.

lazy=true|false
Whether to perform table resolution lazily. If true, each table is only accessed
when the time comes to add its rows to the output; if false, then all the tables
are accessed up front. This is mostly a tuning parameter, and on the whole it
doesn't matter much how it is set, but for joining an enormous number of tables
setting it true may avoid running out of resources.

countrows=true|false
Whether to count the rows in the table before starting the output. This is
essentially a tuning parameter - if writing to an output format which requires the
number of rows up front (such as normal FITS) it may result in skipping the number
of passes through the input files required for processing. Unless you have a good
understanding of the internals of the software, your best bet for working out
whether to set this true or false is to try it both ways

VERSION

       STILTS version 3.2-debian

       This is the Debian version of Stilts, which lack the support  of  some  file  formats  and
       network protocols. For differences see
       file:///usr/share/doc/stilts/README.Debian

AUTHOR