in reply to Summing column values

hi

well as Ratazong said this probably the easiest way to go and here is an example: 


#!/usr/bin/perl

use strict;
#no warnings;

open (IN, "<", $ARGV[0]) || die "$!";
my %hash;

while (<IN>){
  chomp;
  my @array =split(',',$_);
  my $id = substr $array[1], 1,3;
  (defined $hash{$array[0]}{$id}) ? ($hash{$array[0]}{$id} += $array[2
+]) : ($hash{$array[0]}{$id} = $array[2])  ;
} 
close IN;

foreach my $prim (keys %hash){
  foreach my $sec (keys %{$hash{$prim}}){
    print "$prim, $sec, $hash{$prim}{$sec}\n";
  }
}

[download]
hope this helps

baxy

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Re^2: Summing column values
by BrowserUk (Patriarch) on Feb 24, 2010 at 10:25 UTC 

    (defined $hash{$array[0]}{$id}) 
    ? ($hash{$array[0]}{$id} += $array[2]) 
    : ($hash{$array[0]}{$id}  = $array[2]);

    [download]

    That's more complicated than is necessary. Perl's clever enough to know that if you add a number to an undefined variable, to treat that var as 0. This would suffice: 

       $hash{$array[0]}{$id} += $array[2];

    [download]
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