problem using GD::Graph::Histogram

krish28 has asked for the wisdom of the Perl Monks concerning the following question:

Hi all,
I am trying to use the GD::Graph::Histogram module in this code here, to plot counts at locations:

my $graph = new GD::Graph::histogram(4000000,6000000);
$graph -> set(
x_label => 'Location',
y_label => 'Count',
title => 'Sample Histogram',
x_labels_vertical => 1,
bar_spacing => 0,
shadow_depth => 1,
shadowclr => 'dred',
transparent => 0,
)
or warn $graph -> error;
my $gd = $graph -> plot (\@arrayofinterest) or die $graph->error;
open (IMG, '>histo.png') or die $!;
binmode IMG;
print IMG $gd -> png;
[download]

But its not working and i get this error message when i try to run it:

Not a GD::Image object at /usr/lib/perl5/site_perl/5.8.5/GD/Graph.pm l
+ine 180
[download]

Can anyone help?
I've installed GD, GD::Graph and the GD::Graph::Histogram modules, but to no avail!!
Thanks
Krish

Comment on problem using GD::Graph::Histogram Select or Download Code

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Re: problem using GD::Graph::Histogram by zwon (Abbot) on Jan 14, 2010 at 22:56 UTC
Are you sure you have enough RAM for 4000000x6000000 pixels image? ;)	[reply]
Re: problem using GD::Graph::Histogram by Khen1950fx (Canon) on Jan 15, 2010 at 19:37 UTC
I noticed two things: The data set `"\@arrayofinterest"` probably won't work the way that you think. Also, look back at the sample and look at the data set that the author gave. I tried the sample, and it worked fine. It prints the png to the home directory. Here's the sample: `#!/usr/bin/perl use strict; use warnings; use GD::Graph::histogram; my $data = [1,5,7,8,9,10,11,3,3,5,5,5,7,2,2]; my $graph = new GD::Graph::histogram(400,600); $graph -> set( x_label => 'Location', y_label => 'Count', title => 'Sample Histogram', x_labels_vertical => 1, bar_spacing => 0, shadow_depth => 1, shadowclr => 'dred', transparent => 0, ) or warn $graph->error; my $gd = $graph->plot($data) or die $graph->error; open (IMG, '>histo.png') or die $!; binmode IMG; print IMG $gd->png;` [download]	[reply] [d/l] [select]
Re^2: problem using GD::Graph::Histogram by krish28 (Acolyte) on Jan 18, 2010 at 18:18 UTC
Hi Khen, Thanks for the reply. I was planning on using the sample code, but i noticed that the variable "$data" is defined as an array, or thats what my limited knowledge of perl led me to believe..I don't know abt this data type yet.. So i used the sample code as i saw in the GD::Graph module!! I'll try this sample code!! Krish	[reply]