View Full Version : querying numbers in text file

08-05-2002, 09:46 PM
Many thanks in advance for your help! First, I'll show you what I'm trying to do and then the code I'm using.

I'd like to query a text file with the following numbers organized as such:
10 35
20 75
45 50
50 98
36 45

Ave. column 1: 32.2
Ave. column 2: 60.6

So what I'm trying to do first is to query the lines individually and just print the output to see if it's working.

#!/usr/bin/perl -w

use strict;

open DATA, 'data.txt' or die "Can't open data.txt: $!\n";

my @data;

# get the data
while ( <DATA> ) {
my @d = /(\d+)/g;

push @{$data[$_]}, $d[$_] for 0 .. $#d;

for ( @data ) {
# assign line number [x] to a variable
my $line = @$_[0];

# trying to separate the numbers on the line
my @numbers = split (/ /, $line);

# just print the first line's first number
my $test_var = $numbers[0];
print "$test_var\n";

The Output:

Printed both numbers on separate lines. I can't figure out what I'm doing wrong but it must have something to do with my use of 'split'. Good karma points for anyone that helps! TIA!

08-06-2002, 02:01 PM
Hehe, I think lines like this:
push @{$data[$_]}, $d[$_] for 0 .. $#d;

Scare people a bit when they're thinking of replying.

Why not try something simpler, like:

#!/usr/bin/perl -w
use strict;

open (DATA, "data.txt") or die "Can't open data.txt: $!\n";
my @col1, @col2, $temp1, $temp2;

# get the data
while ( <DATA> ) {
($temp1, $temp2) = split;
push (@col1, $temp1);
push (@col2, $temp2);

printf ("Average of first column is %.2d\n", average(\@col1));
printf ("Average of second column is %.2d\n", average(\@col2));

sub average {
my $array = shift;
my $sum;

foreach (@{$array}) {
$sum += $_;

return ($sum / ($#{$array} + 1));
Don't know if that'll work or not, I'm fairly sure it will but I haven't been able to test it yet.