This is as close as I can come, given that the description of how to process data is inconsistent. The trick here is to partition the split data set into an array of genes and an array of spcs and work with that. I'm sure others here can make this prettier code than I.

If you want it spaced nicely, please run a copy of perltidy on this code.

#!/usr/bin/perl

use warnings;
use strict;
#
# %adjacent  - is a hash of arrays.
#              each key contains a cluster identified by the key (root
+).
# %sequences - is a hash of hashes.
#              The first key is identical to a key (root) in %adjacent
+.
#              The second key ids each "spcs" in the cluster.
#              The value is the count of "spc".
#
my %adjacent;
my %sequences;
while (<DATA>) {
    chomp;
    next unless $_ =~ /\w+/;
    my @component = split /\,/, $_;
    my @genes;
    my @spcs;
    for my $element (@component) {
        $element =~ s/\s+$//;
    if ( $element =~ /^Gene/i ) {
        push @genes, $element;
    }
    else {
        push @spcs, $element;
    }
    }
    if ( my $parent = rooted( \@genes ) )  {
    for my $gene (@genes) {
        push @{$adjacent{$parent}}, $gene 
            unless ( has_root($gene));
    }
    for my $species (@spcs) {
        $sequences{$parent}{$species}++;
    }
    }
    else {
    my $root = shift @genes;
    @{$adjacent{$root}} = ();
    for my $gene ( @genes ) {
        push @{$adjacent{$root}}, $gene 
            unless ( has_root($gene));
    }
    for my $species (@spcs) {
        $sequences{$parent}{$species}++;
        }
    }
}
print "*----------------------------------------------*\n";
for my $inner ( sort keys %adjacent ) {
    print "$inner";
    for my $outer ( sort @{$adjacent{$inner}} ) {
        print ",$outer";
    }
    for (sort keys %{$sequences{$inner}}) {
        printf ",%s=%d", $_, $sequences{$inner}{$_};
    }        
    print "\n";
}
sub has_root {
    my $candidate = shift;
    return 0 if ( keys %adjacent < 1);
    for my $inner ( sort keys %adjacent ) {
    if ( $candidate eq $inner ) {
        return $inner;
    }
    for my $outer ( sort @{$adjacent{$inner}} ) {
        if ( $candidate eq $outer ) {
        return $inner;
        }
    }
    }
    return 0;    
}

sub rooted {
    my $aref = shift;
    for (@$aref) {
    my $parent = has_root( $_ );
    return $parent if $parent;
    }
    return 0;
}


__DATA__
Gene1,Gene2,spc1,spc2 
Gene3,Gene1,spc1,spc2,spc4 
Gene4,Gene1,spc1,spc2,spc5,spc3,spc1 
Gene2,Gene3,spc1,spc2 
Gene2,Gene4,spc2,spc3 
Gene3,Gene4,spc1,spc2 
GeneA,GeneB,spc4,spc5 
GeneB,GeneC,spc1,spc2 
GeneC,GeneD,spc1,spc2 
GeneD,GeneE,spc4,spc2 
GeneE,GeneF,spc3,spc1 
GeneX,GeneY,spc6,spc8 
GeneX,GeneY,GeneP,spc1,spc2 
GeneY,spc3,spc4

[download]
With the results: 
C:\Code>perl adjacent.pl
*----------------------------------------------*
Gene1,Gene2,Gene3,Gene4,spc1=5,spc2=5,spc3=2,spc4=1,spc5=1
GeneA,GeneB,GeneC,GeneD,GeneE,GeneF,spc1=3,spc2=3,spc3=1,spc4=1
GeneX,GeneP,GeneY,spc1=1,spc2=1,spc3=1,spc4=1

[download]

In reply to Re^3: Clustering with Perl by dwm042
in thread Clustering with Perl by nerve

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