---
name: "astmatch"
section: "1"
platform: "linux"
package: "gnuastro"
version: "0.23-2+b3"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/astmatch"
---

# astmatch(1)

match catalogs by 1D or 2D positions

## NAME

Match - match catalogs by 1D or 2D positions

## SYNOPSIS

**astmatch** \[*OPTION*...\] *ASTRdata*

## DESCRIPTION

Match is part of GNU Astronomy Utilities 0.23. 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:

-

  Input:

- **-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.

- **--searchin**=*STR*

  Select column(s): 'name', 'unit', 'comment'.

- **--stdintimeout**=*INT*

  Micro-seconds to wait for standard input.

-

  Output:

- **-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

- **--notmatched**

  Output is rows that don't match.

- **--outcols**=*STR*

  Out cols in CSV, 'a': first, 'b': second input.

- **--outfitsnocommit**

  No Git commit in 0-th HDU of output FITS.

- **--outfitsnoconfig**

  No metadata in 0-th HDU of output FITS.

- **--outfitsnodate**

  No 'DATE' in 0-th HDU of output FITS.

- **--outfitsnoversions**

  No versions in 0-th HDU of output FITS.

- **-o**, **--output**=*STR*

  Output file name.

- **--tableformat**=*STR*

  Table fmt: 'fits-ascii', 'fits-binary', 'txt'.

- **--wcslinearmatrix**=*STR*

  WCS linear matrix of output ('pc' or 'cd').

-

  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.

- **--kdtreehdu**=*STR*

  HDU of k-d tree when **--kdtree**=*FILE*.fits.

- **-k**, **--kdtree**=*STR*

  build, internal, disable, CUSTOM-FITS-FILE.

-

  Operating modes:

- \-?, **--help**

  give this help list

- **--checkconfig**

  List all config files and variables read.

- **--cite**

  BibTeX citation for this program.

- **--config**=*STR*

  Read configuration file STR immediately.

- **--config-prefix**=*STR*

  Custom prefix of option names config files.

- **--lastconfig**

  Do not parse any more configuration files.

- **--log**

  Information about output(s) in a log file.

- **--minmapsize**=*INT*

  Min. bytes to avoid RAM automatically.

- **-N**, **--numthreads**=*INT*

  Number of CPU threads to use.

- **--onlyversion**=*STR*

  Only run if the program version is STR.

- **-P**, **--printparams**

  Print parameter values to be used and abort.

- **--quietmmap**

  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.

- **--usage**

  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: http://www.gnu.org/software/gnuastro/

## REPORTING BUGS

Report bugs to bug-gnuastro@gnu.org.

## COPYRIGHT

Copyright © 2015-2024 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

## SEE ALSO

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.