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MATCH(1) User Commands MATCH(1)


Match - match catalogs by 1D or 2D positions


astmatch [OPTION...] ASTRdata


Match is part of GNU Astronomy Utilities 0.14. Match matches catalogs of objects and (by default) will return the re-arranged matching inputs. The optional log file will return low-level information about the match (indexs and distances).

For more information, please run any of the following commands. In particular the second contains a very comprehensive explanation of Match's invocation: expected input(s), output(s), and a full description of all the options.

All options and their values:
$ astmatch -P
Inputs/Outputs and options:
$ info astmatch
Full section in manual/book:
$ info Match
Full Gnuastro manual/book:
$ info gnuastro

If you couldn't find your answer in the manual, you can get direct help from experienced Gnuastro users and developers. For more information, please run:

$ info help-gnuastro

Match options:

-h, --hdu=STR/INT
Extension name or number of first input.
-H, --hdu2=STR/INT
Extension name or number of second input.
-I, --ignorecase
Ignore case in matching/searching columns.
Select column(s): 'name', 'unit', 'comment'.
Micro-seconds to wait for standard input.
-D, --dontdelete
Don't delete output if it exists.
-K, --keepinputdir
Keep input directory for automatic output.
-l, --logasoutput
No rearranging of inputs, output is log file
Output is rows that don't match.
Out cols in CSV, 'a': first, 'b': second input.
-o, --output=STR
Output file name.
Table fmt: 'fits-ascii', 'fits-binary', 'txt'.
Catalog matching
-a, --aperture=FLT[,...]
Acceptable aperture for matching.
-c, --ccol1=STR[,STR]
Column name/number of first catalog.
-C, --ccol2=STR[,STR]
Column name/number of second catalog.
-d, --coord=FLT[,FLT]
Manually input coordiantes.
Operating modes:
-?, --help
give this help list
List all config files and variables read.
BibTeX citation for this program.
Read configuration file STR immediately.
Do not parse any more configuration files.
Information about output(s) in a log file.
Minimum bytes in array to not use ram RAM.
Only run if the program version is STR.
-P, --printparams
Print parameter values to be used and abort.
Don't print mmap'd file's name and size.
-q, --quiet
Only report errors, remain quiet about steps.
-S, --setdirconf
Set default values for this directory and abort.
give a short usage message
-U, --setusrconf
Set default values for this user and abort.
-V, --version
print program version

Mandatory or optional arguments to long options are also mandatory or optional for any corresponding short options.

GNU Astronomy Utilities home page:


Report bugs to


Copyright © 2015-2021, Free Software Foundation, Inc. License GPLv3+: GNU General public license version 3 or later.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.

Written/developed by Mohammad Akhlaghi


The full documentation for Match is maintained as a Texinfo manual. If the info and Match programs are properly installed at your site, the command
info Match

should give you access to the complete manual.

January 2021 GNU Astronomy Utilities 0.14