Hello all, I am trying to use a function that essentially counts matches of a string with a list of strings that have indices. (i.e. 1,"ATAT"\n 2,"GCGC" \n etc.). The code takes two inputs, one is a hash of sequence and index numbers that looks like so

indexfile' => {
                         'GCTCAGGA' => '4',
                         'AGCGTAGC' => '5',
                         'TTCTGCCT' => '3',
                         'CATGCCTA' => '6',
                         'TCGCCTTA' => '1',
                         'GTAGAGAG' => '7',
                         'GCGTAAGA' => '13',
                         'TAGATCGC' => '9',
                         'CTAGTACG' => '2',
                         'CTAAGCCT' => '16',
                         'CTCTCTAT' => '10',
                         'ACTGCATA' => '14',
                         'AGAGTAGA' => '12',
                         'TATCCTCT' => '11',
                         'AAGGAGTA' => '15',
                         'CCTCTCTG' => '8'
                       },

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and the other file is a query sequence string. I want to find the best match between them. The code fails at the line I will comment on, and I would really appreciate any insight into why.

sub match_query(){
    my $indexfile = shift;
    my $queryseq     = shift;
    
    my @match_count;
    for my $key (keys %$indexfile){
        my $count;
        for(my $k=0; $k<length($key)-1; $k++){
            my $k_nuc = substr $key,$k,2;
            for(my $i=0; $i<length($queryseq)-1; $i++){
                my $i_nuc = substr $queryseq,$i,2;
                
                my $rel = $k-$i;
                if($k_nuc eq $i_nuc){
                    $count->{$rel} ||= 0;
                    $count->{$rel}  += 1;
                }else{
                    $count->{$rel} ||= 0;
                    $count->{$rel}  += 0;
                }
            }
        }
        
        my @array = sort{$b <=> $a} values %$count;
        my $max_count = shift @array;
        my $element;
        $element->{bar} = $key;
        $element->{max} = $max_count;
        push @match_count, $element;
    
    }
    my $result;
    @match_count = sort{$b ->{max} <=> $a->{max}} @match_count; #CODE 
+#FAILS HERE DOESNT LIKE ->{max}
    if($match_count[0]->{max} == $match_count[1]->{max}){
        $result = 0;
    }elsif($match_count[0]->{max}>5){
      my $called_bar = $match_count[0]->{bar};
        $result = $indexfile->{$called_bar};
    }else{
       $result = 0;
    }
    return $result
    
}

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If anyone could explain to my why the code fails I would really appreciate it, the error message I recieve looks like this:

Use of uninitialized value in numeric comparison (<=>) at /Users/XXXXX
+X/Desktop/test.pl line 602.

[download]

In reply to Help with function, count matches and store in hash & retrieve sorted by Pathogenomix

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