I have an array containing a set of strings; all strings are of equal length but the length is variable dependent upon user argument. As an example:

AABBC
BAABC
AABBD
AACBB

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I want to calculate the frequency of each unique character present in the collection, at each position across all strings. Using the above strings, the desired result would be:

      A        B      C       D
1    0.75    0.25    0.00    0.00
2    1.00    0.00    0.00    0.00
3    0.25    0.50    0.25    0.00
4    0.00    1.00    0.00    0.00
5    0.00    0.25    0.50    0.25

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Does anybody know of a way to accomplish this in a succinct manner? Currently i've got this chunk of code within my script:

foreach my $segment (@collection) {
    foreach $i (0..length($segment)) {
        if (substr($segment,$i,1) eq "A") {
            $score[$i][1] = 1;
            $score[$i][2] = 0;
            $score[$i][3] = 0;
            $score[$i][4] = 0;
        } elsif (substr($segment,$i,1) eq "B") {
            $score[$i][1] = 0;
            $score[$i][2] = 1;
            $score[$i][3] = 0;
            $score[$i][4] = 0;
        } elsif (substr($segment,$i,1) eq "C") {
            $score[$i][1] = 0;
            $score[$i][2] = 0;
            $score[$i][3] = 1;
            $score[$i][4] = 0;
        } elsif (substr($segment,$i,1) eq "D") {
            $score[$i][1] = 0;
            $score[$i][2] = 0;
            $score[$i][3] = 0;
            $score[$i][4] = 1;
        }
    }
}

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Which is a very long-winded and literal way of thinking about scoring each character (before an average would be taken). I would also need to push the result each time so that multiple segments (strings) could be accommodated - but i'm not sure how and would prefer to find a better way of doing this..

In reply to Tallying overall frequency of characters in a set of strings by position by Anonymous Monk

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