Re: Extract the number of the species for txt file

[choroba]

Extract the counts to a hash:

#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

my %counts;

while (<>) {
    my @species = split;
    my @numbers = split ' ', <>;
    warn "Different number of columns at line $.!" if @species != @num
+bers;
    for my $i (0 .. $#species) {
        push @{ $counts{ $species[$i] } }, $numbers[$i];
    }
}

for my $spec (keys %counts) {
    say $spec;
    for my $count (@{ $counts{$spec} }) {
        say $count;
    }
}

[fan li]

Hi choroba

Thanks for your help. Your code works fine and can out put the all species and corresponding numbers to the screen. However, I just want to extract one specific specie and corresponding number at a time. Meanwhile, the corresponding number should be 0 if there is no such specific specie.And it would be better if the outcome can write into a new text file instead of the screen. Take O4 as an example, there should be just one output and should be like this

O4

0 # There is no “O4” specie in (1), so the corresponding number is 0.

3

0 # There is no “O4” species in (5), so the number is 0 too.

It will be grateful if you can help me.

Fan Li

[choroba]

If you know the species in advance, there's no need to remember the counts for the remaining ones.

#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

say my $search_for_species = 'O4';

while (<>) {
    my %counts;
    my @species = split;
    my @numbers = split ' ', <>;
    warn "Different number of columns at line $.!" if @species != @num
+bers;
    for my $i (0 .. $#species) {
        $counts{ $species[$i] } = $numbers[$i];
    }
    say $counts{$search_for_species} // 0;
}

To output to a file, use redirection:

perl script_from_choroba.pl > new_file