I have an array of 100 floating point values. I rounded the values to the tenths place in order to create more matches on my histogram. I was wondering how to get these values in an array and put them into a histogram. I have previously checked other posts on PerlMonks, but I end up with errors in my code. I am relatively new to programming in general and I might lack certain programming etiquette or syntax.

use strict;
use warnings;
use Data::Dumper;
use 5.010;
use GD::Graph::histogram;
use YAML;
use CGI ':standard';

    
sub main {
    
    my $input = 'distance.txt';
    unless(open(INPUT, $input)) {
        die "\nCannot open input\n";
    }
    
    my @data;
    
    while(my $line = <INPUT>) {
    chomp $line;
    my @rounded = sprintf ("%.1f\n", $line); 
    
    push @data, @rounded;
    
    my ( $filename, @data ) = @_;
    my $graph = new GD::Graph::histogram(400,600);
    $graph->set(
                y_label         => 'Count',
                x_label         => 'Distances',
                title           => 'Histogram',
                x_labels_vertical => 1,
                bar_spacing     => 0,
                shadow_depth    => 1,
                shadowclr       => 'dred',
                transparent     => 0,
        )
        or warn $graph->error;

    my $image = $graph->plot(\@data) or die $graph->error;
    open( IMG, '>' . $filename ) or die $!;
    binmode IMG;
    print IMG $image->png;
    
}
}
main();
[download]

These are the error messages I have been receiving.

 

Subroutine main::Dump redefined at /System/Library/Perl/5.18/CGI.pm li
+ne 308.
Use of uninitialized value $min in subtraction (-) at /Library/Perl/5.
+18/GD/Graph/histogram.pm line 110, <INPUT> line 1.
Use of uninitialized value $max in subtraction (-) at /Library/Perl/5.
+18/GD/Graph/histogram.pm line 110, <INPUT> line 1.
Use of uninitialized value $max in numeric le (<=) at /Library/Perl/5.
+18/GD/Graph/histogram.pm line 118, <INPUT> line 1.
Use of uninitialized value $upper in numeric le (<=) at /Library/Perl/
+5.18/GD/Graph/histogram.pm line 118, <INPUT> line 1.
Use of uninitialized value $lower in addition (+) at /Library/Perl/5.1
+8/GD/Graph/histogram.pm line 119, <INPUT> line 1.
Use of uninitialized value $max in numeric le (<=) at /Library/Perl/5.
+18/GD/Graph/histogram.pm line 122, <INPUT> line 1.
Use of uninitialized value in string eq at /Library/Perl/5.18/GD/Graph
+/histogram.pm line 42, <INPUT> line 1.
Use of uninitialized value in subtraction (-) at /Library/Perl/5.18/GD
+/Graph/histogram.pm line 59, <INPUT> line 1.
Use of uninitialized value in addition (+) at /Library/Perl/5.18/GD/Gr
+aph/histogram.pm line 59, <INPUT> line 1.
Use of uninitialized value $filename in concatenation (.) or string at
+ /Users/Joshua/eclipse-workspace/PlottingPoints/Histogram line 40, <I
+NPUT> line 1.
No such file or directory at /Users/Joshua/eclipse-workspace/PlottingP
+oints/Histogram line 40, <INPUT> line 1.
[download]

2018-07-20 Athanasius added code tags around error messages

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In reply to Histogram Creation by Galahad

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