Re: Getting indices of the same value that occurs multiple times in an array...

[Marshall]

I think that it is easier to use the indexes() function in List::MoreUtils.

the snippet "indexes{/^1$/}@colData" yields the index numbers of elements in @colData that contains just a "1". This is an XS module like List::Util's and runs very fast. Getting the textual name is a simple array look-up. These terms are pushed into a HashOfArray. So, 2 lines of code that do a lot of work!

#!/usr/bin/perl -w
use strict;
use List::MoreUtils qw(indexes);
use Data::Dumper;

my %family_data;
my @dataNames = qw( lacM    taba    mori    glyB    gly4);

<DATA>;   #skip the header line
while (<DATA>)
{
     my ($family, @colData) = split;
     push @{$family_data{$family}}, 
               map{$dataNames[$_]}indexes{/^1$/}@colData;
}

print Dumper(\%family_data);

=prints
$VAR1 = {
          'OG_2' => [
                      'taba',
                      'glyB'
                    ],
          'OG_1' => [
                      'lacM',
                      'mori'
                    ]
        };
=cut        


__DATA__
Family  lacM    taba    mori    glyB    gly4
OG_1    1   0   1   0   0
OG_2    0   1   0   1   0

Of course map{$dataNames[$_]}indexes{/^1$/}@colData;
could be map{$dataNames[$_]}indexes{$_}@colData;
but I thought the regex was less confusing albeit a bit slower.
either way is plausible, take your pick.