package Astro::Catalog::Query::SuperCOSMOS; # Depressingly the generic reg expression used the SkyCat.pm doesn't # seem to work for SuperCOSMOS URL's, eventually we're going to have # to make the regexp more generic. In the interim, I've cut and pasted # the entire module into this sub-class so I can do queries. # # Yes Tim, I know this sucks. =head1 NAME Astro::Catalog::Query::CMC - A query request to the SuperCOSMOS catalogue =head1 SYNOPSIS $supercos = new Astro::Catalog::Query::SuperCOSMOS( RA => $ra, Dec => $dec, Radius => $radius, Nout => $number_out, Colour => $band ); my $catalog = $supercos->querydb(); =head1 WARNING This code totally ignores the epoch of the observations and the associated proper motions, this pretty much means that for astrometric work the catalogues you get back from the query are pretty much bogus. This should be sorted in the next distribution. =head1 DESCRIPTION The module is an object orientated interface to the online SuperCOSMOS catalogue using the generic Astro::Catalog::Query::SkyCat class Stores information about an prospective query and allows the query to be made, returning an Astro::Catalog::Query::SuperCOSMOS object. The object will by default pick up the proxy information from the HTTP_PROXY and NO_PROXY environment variables, see the LWP::UserAgent documentation for details. See L for the catalog-independent methods. =cut # L O A D M O D U L E S -------------------------------------------------- use 5.006; use strict; use warnings; use warnings::register; use base qw/ Astro::Catalog::Transport::REST /; use vars qw/ $VERSION $DEBUG $FOLLOW_DIRS /; use Data::Dumper; use Carp; use File::Spec; use Carp; # generic catalog objects use Astro::Catalog; use Astro::Catalog::Star; '$Revision: 1.9 $ ' =~ /.*:\s(.*)\s\$/ && ($VERSION = $1); $VERSION = '0.01'; $DEBUG = 0; # Controls whether we follow 'directory' config entries and recursively # expand those. Default to false at the moment. $FOLLOW_DIRS = 0; # This is the name of the config file that was used to generate # the content in %CONFIG. Can be different to the contents ofg_file # if that my $CFG_FILE; # This is the content of the config file # organized as a hash indexed by remote server shortname # this has the advantage of removing duplicates my %CONFIG; =head1 REVISION $Id: SuperCOSMOS.pm,v 1.9 2003/09/25 23:33:49 aa Exp $ =head1 METHODS =head2 Constructor =item B Simple constructor, handles the 'Colour' option, e.g. long_name: SuperCOSMOS catalog - blue (UKJ) southern survey short_name: SSScat_UKJ@WFAU long_name: SuperCOSMOS catalog - red (UKR) southern survey short_name: SSScat_UKR@WFAU long_name: SuperCOSMOS catalog - near IR (UKI) southern survey short_name: SSScat_UKI@WFAU long_name: SuperCOSMOS catalog - red (ESOR) southern survey short_name: SSScat_ESOR@WFAU $q = new Astro::Catalog::Query::SuperCOSMOS( colour => 'UKJ', %options ); Allowed options are 'UKJ', 'UKR', 'UKI', and 'ESOR' for the UK Blue, UK Red, UK near-IR and ESO Red catalogues respectively. All other options are passed on to SUPER::new(). =cut sub new { my $proto = shift; my $class = ref($proto) || $proto; # Instantiate via base class my $block = $class->SUPER::new( @_ ); return $block; } =head2 Accessor methods =over 4 =item B<_selected_catalog> Catalog name selected by the user and currently configured for this object. Not to be used outside this class.. =cut sub _selected_catalog { my $self = shift; if (@_) { # The class has to be configured as a hash!!! $self->{SKYCAT_CATALOG} = shift; } #print "\nSuperCOSMOS: _selected_catalog() returning " . # $self->{SKYCAT_CATALOG} . "\n" if $DEBUG; return $self->{SKYCAT_CATALOG}; } =head2 General methods =over 4 =item C Configure the object. This calls the base class configure , after it has made sure that a sky cat config file has been read (otherwise we will not be able to vet the incoming arguments. =cut sub configure { my $self = shift; # load a config if we do not have one read yet # Note that this may force a remote URL read via directory # directives even though we do not have a user agent configured... $self->_load_config() unless %CONFIG; # Error if we have no config yet croak "Error instantiating SuperCOSMOS object since no config was located" unless %CONFIG; # Now we need to configure this object based on the # supplied catalog name. This is not really a public interface # let's call it a protected interface available to subclases # even though we are not technically a subclass... my %args = Astro::Catalog::_normalize_hash(@_); #if( $DEBUG ) { # print "Arguements\n\n"; # foreach my $key ( sort keys %args ) { # print " $key = $args{$key}\n"; # } # print "\n\n"; #} croak "A colour must be provided using the 'colour' key" unless exists $args{colour}; # case-insensitive my $colour = lc($args{colour}); if ( $colour eq 'ukj' ) { $self->_selected_catalog( 'ssscat_ukj@wfau' ); } elsif ( $colour eq 'ukr' ) { $self->_selected_catalog( 'ssscat_ukr@wfau' ); } elsif ( $colour eq 'uki' ) { $self->_selected_catalog( 'ssscat_uki@wfau' ); } elsif ( $colour eq 'esor' ) { $self->_selected_catalog( 'ssscat_esor@wfau' ); } else { # default to UKR $self->_selected_catalog( 'SSScat_UKR@WFAU' ); } # Configure $self->SUPER::configure( %args ); } =item B<_build_query> Construct a query URL based on the options. $url = $q->_build_query(); =cut sub _build_query { my $self = shift; my $cat = $self->_selected_catalog(); # Get the URL my $url = $CONFIG{$cat}->{url}; # Translate all the options to the internal skycat format my %translated = $self->_translate_options(); #print "Translated query: ".Dumper(\%translated,$url) if $DEBUG; # Now for each token replace it in the URL for my $key (keys %translated) { my $tok = "%". $key; croak "Token $tok is mandatory but was not specified" unless defined $translated{$key}; $url =~ s/$tok/$translated{$key}/; } #print "Final URL: $url\n"; return $url; } =item B<_parse_query> All the SkyCat servers return data in TST format. Need to make sure that column information is passed into the TST parser. =cut sub _parse_query { my $self = shift; # Get the catalog info my $cat = $self->_selected_catalog(); # and extract formatting information needed by the TST parser my %params; for my $key (keys %{ $CONFIG{$cat} }) { if ($key =~ /_col$/) { #print "FOUND $key in column $CONFIG{$cat}->{$key}\n" if $DEBUG; $params{$key} = $CONFIG{$cat}->{$key}; } } # Time to pad the params with known values, this is yet another un-Godly # hack for which I'm duely ashamed. God help us if they ever change the # catalogues. Why is SuperCOSMOS so much bloody trouble? #print $self->{BUFFER} ."\n" if $DEBUG; # Make sure we set origin and field centre if we know it my $query = new Astro::Catalog( Format => 'TST', Data => $self->{BUFFER}, ReadOpt => \%params, Origin => $CONFIG{$cat}->{long_name} ); # Grab each star in the catalog and add some value to it my $catalog = new Astro::Catalog( ); $catalog->origin( $query->origin() ); $catalog->set_coords( $query->get_coords() ) if defined $query->get_coords(); my ( @oldstars, @newstars ); @oldstars = $query->allstars(); foreach my $i ( 0 ... $#oldstars ) { my $star = $oldstars[$i]; #print Dumper( $star ); # if we have a non-zero quality, set the quality to 1 (this sucks!) $star->quality(1) if( $star->quality() != 0 ); # calulate the errors if ( $star->get_magnitude( "BJ" ) != 99.999 ) { $star->magerr( {BJ => 0.04} ); $star->magerr( {BJ => 0.04} ) if( $star->get_magnitude( "BJ" ) > 15.0 ); $star->magerr( {BJ => 0.05} ) if( $star->get_magnitude( "BJ" ) > 17.0 ); $star->magerr( {BJ => 0.06} ) if( $star->get_magnitude( "BJ" ) > 19.0 ); $star->magerr( {BJ => 0.07} ) if( $star->get_magnitude( "BJ" ) > 20.0 ); $star->magerr( {BJ => 0.12} ) if( $star->get_magnitude( "BJ" ) > 21.0 ); $star->magerr( {BJ => 0.08} ) if( $star->get_magnitude( "BJ" ) > 22.0 ); } else { $star->magerr( {BJ => 99.999} ); } if ( $star->get_magnitude( "R1" ) != 99.999 ) { $star->magerr( {R1 => 0.06} ); $star->magerr( {R1 => 0.06} ) if( $star->get_magnitude( "R1" ) > 11.0 ); $star->magerr( {R1 => 0.03} ) if( $star->get_magnitude( "R1" ) > 12.0 ); $star->magerr( {R1 => 0.09} ) if( $star->get_magnitude( "R1" ) > 13.0 ); $star->magerr( {R1 => 0.10} ) if( $star->get_magnitude( "R1" ) > 14.0 ); $star->magerr( {R1 => 0.12} ) if( $star->get_magnitude( "R1" ) > 18.0 ); $star->magerr( {R1 => 0.18} ) if( $star->get_magnitude( "R1" ) > 19.0 ); } else { $star->magerr( {R1 => 99.999} ); } if ( $star->get_magnitude( "R2" ) != 99.999 ) { $star->magerr( {R2 => 0.02} ); $star->magerr( {R2 => 0.02} ) if( $star->get_magnitude( "R2" ) > 12.0 ); $star->magerr( {R2 => 0.03} ) if( $star->get_magnitude( "R2" ) > 13.0 ); $star->magerr( {R2 => 0.04} ) if( $star->get_magnitude( "R2" ) > 15.0 ); $star->magerr( {R2 => 0.05} ) if( $star->get_magnitude( "R2" ) > 17.0 ); $star->magerr( {R2 => 0.06} ) if( $star->get_magnitude( "R2" ) > 18.0 ); $star->magerr( {R2 => 0.11} ) if( $star->get_magnitude( "R2" ) > 19.0 ); $star->magerr( {R2 => 0.16} ) if( $star->get_magnitude( "R2" ) > 20.0 ); } else { $star->magerr( {R2 => 99.999} ); } if ( $star->get_magnitude( "I" ) != 99.999 ) { $star->magerr( {I => 0.05} ); $star->magerr( {I => 0.05} ) if( $star->get_magnitude( "I" ) > 15.0 ); $star->magerr( {I => 0.06} ) if( $star->get_magnitude( "I" ) > 16.0 ); $star->magerr( {I => 0.09} ) if( $star->get_magnitude( "I" ) > 17.0 ); $star->magerr( {I => 0.16} ) if( $star->get_magnitude( "I" ) > 18.0 ); } else { $star->magerr( {I => 99.999} ); } # calculate colours UKST Bj - UKST R, UKST Bj - UKST I if ( $star->get_magnitude( "BJ" ) != 99.999 && $star->get_magnitude( "R2" ) != 99.999 ) { my $bj_minus_r2 = $star->get_magnitude( "BJ" ) - $star->get_magnitude( "R2" ); $bj_minus_r2 = sprintf("%.4f", $bj_minus_r2 ); $star->colours( {"BJ-R2" => ( $bj_minus_r2 )} ); } else { $star->colours( {"BJ-R2" => 99.999 } ); } if ( $star->get_magnitude( "BJ" ) != 99.999 && $star->get_magnitude( "I" ) != 99.999 ) { my $bj_minus_i = $star->get_magnitude( "BJ" ) - $star->get_magnitude( "I" ); $bj_minus_i = sprintf("%.4f", $bj_minus_i ); $star->colours( {"BJ-I" => ( $bj_minus_i )} ); } else { $star->colours( {"BJ-I" => 99.999 } ); } # calculate colour errors if ( $star->get_magnitude( "BJ" ) != 99.999 && $star->get_magnitude( "R2" ) != 99.999 ) { my $delta_bjmr = ( ( $star->get_errors( "BJ" ) )**2.0 + ( $star->get_errors( "R2" ) )**2.0 )** (1/2); $delta_bjmr = sprintf("%.4f", $delta_bjmr ); $star->colerr( {"BJ-R2" => $delta_bjmr} ); } else { $star->colerr( {"BJ-R2" => 99.999 } ); } if ( $star->get_magnitude( "BJ" ) != 99.999 && $star->get_magnitude( "I" ) != 99.999 ) { my $delta_bjmi = ( ( $star->get_errors( "BJ" ) )**2.0 + ( $star->get_errors( "I" ) )**2.0 )** (1/2); $delta_bjmi = sprintf("%.4f", $delta_bjmi ); $star->colerr( {"BJ-I" => $delta_bjmi} ); } else { $star->colerr( {"BJ-I" => 99.999 } ); } # push it onto the stack $newstars[$i] = $star if defined $star; } $catalog->pushstar( @newstars ); # set the field centre my %allow = $self->_get_allowed_options(); my %field; for my $key ("ra","dec","radius") { if (exists $allow{$key}) { $field{$key} = $self->query_options($key); } } $catalog->fieldcentre( %field ); return $catalog; } =item B<_get_allowed_options> This method declares which options can be configured by the user of this service. Generated automatically by the skycat config file and keyed to the requested catalog. =cut sub _get_allowed_options { my $self = shift; my $cat = $self->_selected_catalog(); #print "SuperCOSMOS.pm: \$CONFIG{\$cat} = $CONFIG{$cat}\n" if $DEBUG; return %{ $CONFIG{$cat}->{allow} }; } =item B<_get_default_options> Get the default options that are relevant for the selected catalog. %defaults = $q->_get_default_options(); =cut sub _get_default_options { my $self = shift; # Global skycat defaults my %defaults = ( # Target information ra => undef, dec => undef, id => undef, # Limits radmin => 0, radmax => 5, width => 10, height => 10, magfaint => 100, magbright => 0, nout => 20000, cond => '', ); # Get allowed options my %allow = $self->_get_allowed_options(); # Trim the defaults (could do with hash slice?) my %trim = map { $_ => $defaults{$_} } keys %allow; return %trim; } =item B<_get_supported_init> =cut sub _get_supported_init { croak "xxx - get supported init"; } =head2 Class methods These methods are not associated with any particular object. =item B Location of the skycat config file. Default location is C<$PERLPREFIX/etc/sss.cfg>. =cut # set or get the cfg_file() name sub cfg_file { my $class = shift; my $cfg_file; if (@_) { $cfg_file = shift; $class->_load_config() || ($cfg_file = undef); } else { # generate the default path to the $PERLPRFIX/etc/sss.cfg file, # this is a horrible hack, there is probably an elegant way to do # this but I can't be bothered looking it up right now. my $perlbin = $^X; my ($volume, $dir, $file) = File::Spec->splitpath( $perlbin ); my @dirs = File::Spec->splitdir( $dir ); my @path; foreach my $i ( 0 .. $#dirs-2 ) { push @path, $dirs[$i]; } my $directory = File::Spec->catdir( @path, 'etc' ); # reset to the default $cfg_file = File::Spec->catfile( $directory, "sss.cfg" ); # debugging and testing purposes unless ( -f $cfg_file ) { # use blib version! $cfg_file = File::Spec->catfile( '.', 'etc', 'sss.cfg' ); } } print "SuperCOSMOS.pm: \$cfg_file in cfg_file() is $cfg_file\n" if $DEBUG; return $cfg_file; } =begin __PRIVATE_METHODS__ =head2 Internal methods =over 4 =item B<_load_config> Method to load the skycat config information into the class and configure the modules. $q->_load_config() or die "Error loading config"; The config file name is obtained from the C method. Returns true if the file was read successfully and contained at least one catalog server. Otherwise returns false. Requires an object to attach itself to (mainly for the useragent remote directory follow up). The results of this load are visible to all instances of this class. Usually called automatically from the constructor if a config has not previously been read. =cut sub _load_config { my $self = shift; my $cfg = $self->cfg_file; #print "SuperCOSMOS.pm: \$cfg = $cfg\n" if $DEBUG; if (!defined $cfg) { warnings::warnif("Config file not specified (undef)"); return; } unless (-e $cfg) { my $xcfg = (defined $cfg ? $cfg : "" ); return; } my $fh; unless (open $fh, "<$cfg") { warnings::warnif( "Specified config file, $cfg, could not be opened: $!"); return; } # Need to read the contents into an array my @lines = <$fh>; # Process the config file and extract the raw content my @configs = $self->_extract_raw_info( \@lines ); #print "Pre-filtering has \@configs " . @configs . " entries\n" if $DEBUG; # Close file close( $fh ) or do { warnings::warnif("Error closing config file, $cfg: $!"); return; }; # Get the token mapping for validation my %map = $self->_token_mapping; # Currently we are only interested in catalog, namesvr and archive # so throw everything else away @configs = grep { $_->{serv_type} =~ /(namesvr|catalog|archive)/ } @configs; #print "Post-filtering has \@configs " . @configs . " entries\n" if $DEBUG; # Process each entry. Mainly URL processing for my $entry ( @configs ) { # Skip if we have already analysed this server if (exists $CONFIG{lc($entry->{short_name})}) { #print "Already know about " . $entry->{short_name} . "\n" if $DEBUG; next; } #print "Processing " . $entry->{short_name} . "\n\n" if $DEBUG; #print Dumper( $entry ) . "\n" if( $DEBUG ); # Extract info from the 'url'. We need to extract the following info: # - Host name and port # - remaining url path # - all the CGI options including the static options # Note that at the moment we do not do token replacement (the # rest of the REST architecture expects to get the above # information separately). This might well prove to be silly # since we can trivially replace the tokens without having to # reconstruct the url. Of course, this does allow us to provide # mandatory keywords. $url =~ s/\%ra/$ra/; if ( $entry->{url} =~ m|^http://www-wfau.roe.ac.uk/~sss/cgi-bin/gaia_obj.cgi? (.*) # CGI options without trailing space |x) { $entry->{remote_host} = "www-wfau.roe.ac.uk"; $entry->{url_path} = "~sss/cgi-bin/gaia_obj.cgi?"; my $options = $1; # if first character is & we append that to url_path since it # is an empty argument $entry->{url_path} .= "&" if $options =~ s/^\&//; # In general the options from skycat files are a real pain # Most of them have nice blah=%blah format but there are some cases # that do ?%ra%dec or coords=%ra %dec that just cause more trouble # than they are worth given the standard URL constructor that we # are attempting to inherit from REST # Best idea is not to fight against it. Extract the host, path # and options separately but simply use token replacement when it # comes time to build the URL. This will require that the url # is moved into its own method in REST.pm for subclassing. # We still need to extract the tokens themselves so that we # can generate an allowed options list. # tokens have the form %xxx but we have to make sure we allow # %mime-type. Use the /g modifier to get all the matches my @tokens = ( $options =~ /(\%[\w\-]+)/g); # there should always be tokens. No obvious way to reomve the anomaly warnings::warnif( "No tokens found in $options!!!" ) unless @tokens; # Just need to make sure that these are acceptable tokens # Get the lookup table and store that as the allowed options my %allow; for my $tok (@tokens) { # only one token. See if we recognize it my $strip = $tok; $strip =~ s/%//; if (exists $map{$strip}) { if (!defined $map{$strip}) { warnings::warnif("Do not know how to process token $tok" ); } else { $allow{ $map{$strip} } = $strip; } } else { warnings::warnif("Token $tok not currently recognized") unless exists $map{$strip}; } } # Store them $entry->{tokens} = \@tokens; $entry->{allow} = \%allow; #print Dumper( $entry ) if $DEBUG; # And store this in the config. Only store it if we have # tokens $CONFIG{lc($entry->{short_name})} = $entry; } # if entry } # for loop # Debug #print Dumper(\%CONFIG) if $DEBUG; return; } =item B<_extract_raw_info> Go through a skycat.cfg file and extract the raw unprocessed entries into an array of hashes. The actual content of the file is passed in as a reference to an array of lines. @entries = $q->_extract_raw_info( \@lines ); This routine is separate from the main load routine to allow recursive calls to remote directory entries. =cut sub _extract_raw_info { my $self = shift; my $lines = shift; # Now read in the contents my $current; # Current server spec my @configs; # Somewhere temporary to store the entries for my $line (@$lines) { # Skip comment lines and blank lines next if $line =~ /^\s*\#/; next if $line =~ /^\s*$/; if ($line =~ /^(\w+):\s*(.*?)\s*$/) { # This is content my $key = $1; my $value = $2; # Assume that serv_type is always first if ($key eq 'serv_type') { # Store previous config if it contains something # If it actually contains information on a serv_type of # directory we can follow the URL and recursively expand # the content push(@configs, $self->_dir_check( $current )); # Clear the config and store the serv_type $current = { $key => $value }; } else { # Just store the key value pair $current->{$key} = $value; } } else { # do not know what this line signifies since it is # not a comment and not a content line warnings::warnif("Unexpected line in config file: $line\n"); } } # Last entry will still be in %$current so store it if it contains # something. push(@configs, $self->_dir_check( $current )); # Return the entries return @configs; } =item B<_dir_check> If the supplied hash reference has content, look at the content and decide whether you simply want to keep that content or follow up directory specifications by doing a remote URL call and expanding that directory specification to many more remote catalogue server configs. @configs = $q->_dir_check( \%current ); Returns the supplied argument, additional configs derived from that argument or nothing at all. Do not follow a 'directory' link if we have already followed a link with the same short name. This prevents infinite recursion when the catalog pointed to by 'catalogs@eso' itself contains a reference to 'catalogs@eso'. =cut my %followed_dirs; sub _dir_check { my $self = shift; my $current = shift; if (defined $current && %$current) { if ($current->{serv_type} eq 'directory') { # Get the content of the URL unless we are not # reading directories if ($FOLLOW_DIRS && defined $current->{url} && !exists $followed_dirs{$current->{short_name}}) { print "Following directory link to ". $current->{short_name}. "[".$current->{url}."]\n" if $DEBUG; # Indicate that we have followed this link $followed_dirs{$current->{short_name}} = $current->{url}; # Retrieve the url, pass that array to the raw parser and then # return any new configs to our caller # Must force scalar context to get array ref # back rather than a simple list. return $self->_extract_raw_info(scalar $self->_get_directory_url( $current->{url} )); } } else { # Not a 'directory' so this is a simple config entry. Simply return it. return ($current); } } # return empty list since we have no value return (); } =item B<_get_directory_url> Returns the content of the remote directory URL supplied as argument. In scalar context returns reference to array of lines. In list context returns the lines in a list. \@lines = $q->_get_directory_url( $url ); @lines = $q->_get_directory__url( $url ); If we have an error retrieving the file, just return an empty array (ie skip it). =cut sub _get_directory_url { my $self = shift; my $url = shift; # Call the base class to get the actual content my $content = ''; eval { $content = $self->_fetch_url( $url ); }; # Need an array my @lines; @lines = split("\n", $content) if defined $content; if (wantarray) { return @lines; } else { return \@lines; } } =item B<_token_mapping> Provide a mapping of tokens found in SkyCat config files to the internal values used generically by Astro::Catalog::Query classes. %map = $class->_token_mappings; Keys are skycat tokens. =cut sub _token_mapping { return ( id => 'id', ra => 'ra', dec => 'dec', # Arcminutes r1 => 'radmin', r2 => 'radmax', w => 'width', h => 'height', n => 'nout', # which filter??? m2 => 'magfaint', m1 => 'magbright', # Is this a conditional? cond => 'cond', # Not Yet Supported cols => undef, 'mime-type' => undef, ws => undef, ); } =back =head2 Translations SkyCat specific translations from the internal format to URL format go here. RA/Dec must match format described in http://vizier.u-strasbg.fr/doc/asu.html (at least for GSC) ie hh:mm:ss.s+/-dd:mm:ss or decimal degrees. =over 4 =cut sub _from_dec { my $self = shift; my $dec = $self->query_options("dec"); my %allow = $self->_get_allowed_options(); # Need colons $dec =~ s/\s+/:/g; # Need a + preprended $dec = "+" . $dec if $dec !~ /^[\+\-]/; return ($allow{dec},$dec); } sub _from_ra { my $self = shift; my $ra = $self->query_options("ra"); my %allow = $self->_get_allowed_options(); # need colons $ra =~ s/\s+/:/g; return ($allow{ra},$ra); } =item B<_translate_one_to_one> Return a list of internal options (as defined in C<_get_allowed_options>) that are known to support a one-to-one mapping of the internal value to the external value. %one = $q->_translate_one_to_one(); Returns a hash with keys and no values (this makes it easy to check for the option). This method also returns, the values from the parent class. =cut sub _translate_one_to_one { my $self = shift; # convert to a hash-list return ($self->SUPER::_translate_one_to_one, map { $_, undef }(qw/ cond /) ); } =back =end __PRIVATE_METHODS__ =head1 COPYRIGHT Copyright (C) 2001 University of Exeter. All Rights Reserved. Some modifications copyright (C) 2003 Particle Physics and Astronomy Research Council. All Rights Reserved. This program was written as part of the eSTAR project and is free software; you can redistribute it and/or modify it under the terms of the GNU Public License. =head1 AUTHORS Alasdair Allan Eaa@astro.ex.ac.ukE =cut # L A S T O R D E R S ------------------------------------------------------ 1;