You probably want hashes instead of arrays. Here's how I would do it, assuming three integers per line: 
my %data;
while (<>) {
    my ($id1, $id2, $int) = split;
    $data{$id1}{$id2} = $int;
}

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In reply to Re: Associated lists to matrices - and accumalted integers by JavaFan
in thread RESOLVED - Associated lists to matrices - and accumalted integers by jaybode

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