Re^3: memory issues

[Anonymous Monk]

Just a small hint to reduce the verboseness of your code:

    ($ipairs{$fk}{$dline}{'head'}, $ipairs{$fk}{$dline}{'effect'}, $ip
+airs{$fk}{$dline}{'pvalue'}) = $ldata{$dline} =~ /^(.*)\s+(\d\.\d+)\s
++\d\.\d+\s+(\d\.\d+)$/;

can be rewritten using a hash slice like this:

    ( @{ $ipairs{$fk}{$dline} }{qw/head effect pvalue/} ) = $ldata{$dl
+ine} =~ /^(.*)\s+(\d\.\d+)\s+\d\.\d+\s+(\d\.\d+)$/;

Otherwise, your code benefits from a temporary variable or two. Here I repurpose $pvt (not sure if the variable name makes sense after that):

    $pvt = $ipairs{$fk}{$pair};
    if($pvt->{'pvalue'}){
        unless($hl){
            $hl = $pvt->{'head'};
        }
        $n++;
        $z+= qnorm($pvt->{'pvalue'});
    }

(This only works because there already exists a hash reference at $ipairs{$fk}{$pair}. It would not work if you tried to say $pvt = {}, but %$pvt = () would. It's all reference magic and not really easy to explain unless you first understand pointers.)

(Of course, the hash slice can be rewritten using a temporary variable, too. It's always a good idea to use temporary variables if it makes your code easier to understand. Triply a good idea if it reduces repetition.)