#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;
use GD::Graph::histogram;

sub createGraphs {
    my ( $HoHoA ) = @_;

    for my $hashRef ( keys %$HoHoA ) {
	for my $line ( sort keys %{ $HoHoA->{$hashRef} } ) {
	    my $graph = new GD::Graph::histogram(400,600);

	    $graph->set( x_label         => 'X Label',
			 y_label         => 'Count',
			 title           => "Histogram From: $hashRef line number $line",
			 x_labels_vertical => 1,
			 bar_spacing     => 0,
			 shadow_depth    => 1,
			 shadowclr       => 'dred',
			 transparent     => 0,
		) or warn $graph->error;

	    my $gd = $graph->plot($HoHoA->{$hashRef}{$line})
		or die $graph->error;

	    open(my $IMG, ">", substr($hashRef, 0, -4).'_'.$line.'.png')
		or die "Unable to save the graph: $!";
	    binmode $IMG;
	    print $IMG $gd->png;
	    close($IMG)
		or die "Unable to close image save: $!";
	}
    }
    return;
}

my %HoHoA;
while (<>) {
    chomp;
    push @{ $HoHoA{$ARGV}{$.} }, split(/,/, )
	if (index($_, ',') != -1);
} continue {
    close ARGV if eof;
}

# print Dumper \%HoHoA; # view the complex structure
createGraphs( \%HoHoA );

__DATA__

~/PerlMonks$ cat data.txt
1,5,7,8,9,10,11,3,3,5,5,5,7,2,2
2,6,7,8,9,15,17,3,4,5,6,5,7,2,3

__END__

~/PerlMonks$ ls -la | grep data
-rw-r--r--  1 user user 2080 Sep  1 01:48 data_1.png
-rw-r--r--  1 user user 2015 Sep  1 01:48 data_2.png
-rw-r--r--  1 user user   64 Sep  1 01:47 data.txt