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Astro::Correlate::Method::FINDOFF - Correlation using Starlink FINDOFF.


  ( $corrcat1, $corrcat2 ) = Astro::Correlate::Method::FINDOFF->correlate( catalog1 => $cat1, catalog2 => $cat2 );


This class implements catalogue cross-correlation using Starlink's FINDOFF application.


General Methods


Cross-correlates two catalogues.

  ( $corrcat1, $corrcat2 ) = Astro::Correlate::Method::FINDOFF->correlate( catalog1 => $cat1,
                                                                           catalog2 => $cat2 );

This method takes two mandatory arguments, both Astro::Catalog objects. It returns two Astro::Catalog objects containing Astro::Catalog::Star objects that matched spatially between the two input catalogues. The first returned catalogue contains matched objects from the first input catalogue, and ditto for the second. The Astro::Catalog::Star objects in the returned catalogues are not in the original order, nor do they have the same IDs as in the input catalogues. A matched object has the same ID in the two returned catalogues, allowing for further comparisons between matched objects.

This method takes the following optional named arguments:

keeptemps - If this argument is set to true (1), then this method will keep temporary files used in processing. Defaults to false.
messages - If set to true (1), then this method will print messages from the FINDOFF task during processing. Defaults to false.
temp - Set the directory to hold temporary files. If not set, then a new temporary directory will be created using File::Temp.
timeout - Set the time in seconds to wait for the CCDPACK monolith to time out. Defaults to 60 seconds.
verbose - If this argument is set to true (1), then this method will print progress statements. Defaults to false.

This method uses the Starlink FINDOFF task, which is part of CCDPACK. In order for this method to work it must be able to find FINDOFF. It first looks in the directory pointed to by the CCDPACK_DIR environment variable, then it looks in the Starlink binary files directory pointed to by the Starlink::Config module, with /ccdpack appended. If either of these fail, then this method will croak. See the Starlink::Config module for information on overriding the base Starlink directory for non-standard installations.


Astro::Correlate, Starlink::Config

Starlink User Note 139.




Brad Cavanagh <>


Copyright (C) 2005 Particle Physics and Astronomy Research Council. All Rights Reserved.

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place,Suite 330, Boston, MA 02111-1307, USA