Re: How can you make this script general?

If all you need to do is calculate the sums then this might help:

my %count;
while (my $line = <DATA>) {
    chomp $line;
    my @cols = split("\t",$line);
    $count{$_} += $cols[$_] for 0 .. $#cols;
}
for my $col_num (sort { $a <=> $b } keys %count) {
    print "Total for column $col_num: $count{$col_num}\n";
}

__DATA__
1    2    3    4
3    4    5    6
6    7    8    9
[download]

Output:

Total for column 0: 10
Total for column 1: 13
Total for column 2: 16
Total for column 3: 19
[download]

Comment on Re: How can you make this script general? Select or Download Code

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Re^2: How can you make this script general? by BrowserUk (Patriarch) on Mar 08, 2014 at 20:33 UTC
Why use a hash and then have to sort, when the column numbers are ... well, numbers? With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply]
Re^3: How can you make this script general? by tangent (Parson) on Mar 08, 2014 at 21:36 UTC
Why use a hash and then have to sort Just a habit really. An array would be more efficient.	[reply]
Re^3: How can you make this script general? by soonix (Chancellor) on Mar 08, 2014 at 21:05 UTC
perhaps tangent wants to be prepared for the general case, where the columns have names...	[reply]
Re^4: How can you make this script general? by BrowserUk (Patriarch) on Mar 08, 2014 at 22:01 UTC
to be prepared for the general case, where the columns have names... Still makes no sense to waste cycles sorting hash keys: `#! perl -slw use strict; my @colnames = split ' ', <DATA>; my @totals; while( <DATA> ) { my @cols = split; $totals[ $_ ] += $cols[ $_ ] for 0 .. $#cols; } printf "%10s:%u\n", $colnames[$_], $totals[$_] for 0 .. $#totals; __DATA__ alpha beta gamma delta 1 2 3 4 5 6 7 8 9 10 11 12` [download] Produces: `C:\test>junk alpha:15 beta:18 gamma:21 delta:24` [download] With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday' Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. i	[reply] [d/l] [select]