I'm not entirely sure what the best way to explain this is, but here goes. I'm trying to create a graph. i have a text file that looks something like this 
-70.6     -27.5 
 -60.8      52.9
-123.0    -132.9 
 110.1     119.9 
 -62.4     -45.6

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I am currently trying to write a perl script to do the following

Convert the numbers so instead of being between -180 and 180 they are between 0 and 360.
Place the resulting x, y values into blocks of 5. So, now if we have a value of 12.3 it's now placed in the '10-15' block (I hope that makes sense).
Create a two dimensional array, and using the blocked x y values, increment the corresponding element of the array by one
This is what I have managed so far. 

#!/usr/bin/perl

use strict;
use warnings;
my $input = $ARGV[0];
my $x = 0;
my $y = 0;
my $zeroed_x = 0;
my $zeroed_y = 0;
my $binned_x = 0;
my $binned_y = 0;
my @binarray = ();

open(INPUT, "$input") || die "Oops! Can't open INPUT file: $!\n";

while(<INPUT>)
{

    $x = substr($_, 0, 6);
    $y = substr($_, 7, 6);
    $zeroed_x = ConvertToFromZero($x);
    $zeroed_y = ConvertToFromZero($y);
    $binned_x = BinAngles($zeroed_x);
    $binned_y = BinAngles($zeroed_y);

    $binarray[$binned_x][$binned_y]++;

}

for(my $i = 0; $i < @binarray; $i++)
{
    for(my $j = 0; $j < @binarray; $j++)
    {
    print "$binarray[$i][$j]\n";
    }
}


######################################################

sub ConvertToFromZero
{

    my ($axis) = @_;
    my $zeroed_axis = 0;

    $zeroed_axis = 180 + $axis;
    return($zeroed_axis);


}

#######################################################

sub BinAngles
{

    my ($axisforbin) = @_;
    my $binnedaxis = 0;

    $binnedaxis = int($axisforbin/5);
    return($binnedaxis);


}

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I get the following error which I don't understand (google doesn't help) 
Use of uninitialized value in concatenation (.) or string at ./script.
+pl line 34, <INPUT> line 22.

[download]
Any suggestions much appreciated.

In reply to Problems processing data for graph by Angharad

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