Thank You very much. The example is working. 
since i need 3 histograms, I tried using subroutine call to draw the h
+istogram chart & i am not getting the results. 

the code in main is as follows:

my $image2 = Covarion_Modules::draw_hist(\@hist);
open(IMG, '>hist.png') or die $!;
binmode IMG;
print IMG $image2->png;

and the subroutine is :

sub draw_hist{

my ($h) = @_;

use CGI ':standard';
use GD::Graph::histogram;

@data = @$h;
my $graph = new GD::Graph::histogram(400,600);

$graph->set(
                y_label         => 'Count',
                x_label         => 'Data',
                title           => 'A Histogram Chart',
                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 $graph->error;
return($image);
}


I am getting the error:

Useless use of a constant in void context at /usr/lib/perl5/site_perl/
+5.8.0/GD/Graph/histogram.pm line 203.
Use of uninitialized value in string eq at /usr/lib/perl5/site_perl/5.
+8.0/GD/Graph/histogram.pm line 42.
Argument "" isn't numeric in numeric eq (==) at /usr/lib/perl5/site_pe
+rl/5.8.0/GD/Graph/histogram.pm line 181.
Use of uninitialized value in string eq at /usr/lib/perl5/site_perl/5.
+8.0/GD/Graph/histogram.pm line 42.
Use of uninitialized value in string eq at /usr/lib/perl5/site_perl/5.
+8.0/GD/Graph/histogram.pm line 42.


any suggestions please

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In reply to Re^2: Histogram in Perl by Jaya
in thread Histogram in Perl by Jaya

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