Try this (produces this):

use Data::Dump qw[ pp ];
use GD::Graph::bars;
use GD::Graph::hbars;

my @data = (
    [ qw[Jan _ Feb _ Mar _ Apr _ May _ Jun _ Jul _ Aug _ Sep _ Oct _ N
+ov _ Dec _ ] ],
    [ map rand( 25 ), 1 .. 24 ],
    [ map rand( 25 ), 1 .. 24 ],
);

for my $my_graph (GD::Graph::hbars->new( 800, 600 ) ) {

    $my_graph->set(
        title => 'Stacked Bars (incremental)',
        x_label => 'X Label', y_label => 'Y label',
        cumulate => 1,
        overwrite => 1,
        borderclrs => $my_graph->{dclrs},
        bar_spacing => 20,
        bar_width => 10,
        transparent => 0,
    );

    $my_graph->set_legend( qw(offset increment more));
    $my_graph->plot(\@data);
    save_chart($my_graph, "test.png");
}
system 1, 'test.png';



sub save_chart
{
    my $chart = shift or die "Need a chart!";
    my $name = shift or die "Need a name!";
    local(*OUT);

    open(OUT, ">$name") or
        die "Cannot open $name.$ext for write: $!";
    binmode OUT;
    print OUT $chart->gd->png;
    close OUT;
}
[download]

If you want different colours then you could create a 4 stack bar but use only 2 of the stack, the other 2 set to zero and alternate the 2 used. For example ;

#!perl
use GD::Graph::bars; 
use GD::Graph::hbars; 

my @data = ( 
['Mar1','Mar2','Apr1','Apr2','May1','May2'],
[1,0,2,0,4,0], 
[2,0,1,0,5,0], 
[0,3,0,3,0,6], 
[0,4,0,4,0,7],
); 
 
my @names = qw/sample15 sample15-h/; 

for my $my_graph (GD::Graph::bars->new, GD::Graph::hbars->new) 
{ 
  my $name = shift @names; 
  print STDERR "Processing $name\n"; 

  $my_graph->set( 
   x_label => 'X Label', 
   y_label => 'Y label', 
   title => 'Stacked Bars (incremental)', 
   cumulate => 1, 
   overwrite => 1,
   borderclrs => $my_graph->{dclrs}, 
   bar_spacing => 5, 
   transparent => 0, 
  ); 

  $my_graph->set_legend( qw(A B C D)); 
  my $gd = $my_graph->plot(\@data); 
  open(IMG, '>',$name.'.gif') or die $!;
  binmode IMG;
  print IMG $gd->gif;
  close IMG;
}
[download]

#!/usr/bin/perl
use strict;
use GD;
use GD::Graph::mixed;
use GD::Graph::colour;
use GD::Graph::bars; 
use GD::Graph::hbars; 
use GD::Graph::Data;
use GD::Text;
use GD::Graph::pie;
#use GD::Font;
my @data = (  
['Mon','-','Tues','-','Wed','-'],
[10,0,40,0,80,0], 
[30,0,50,0,90,0], 
[0,100,0,60,0,30], 
[0,60,0,70,0,50],
); 
 
my @names = qw/sample15 sample15-h/; 
for my $my_graph (GD::Graph::bars->new, GD::Graph::hbars->new)
{ 
  my $name = shift @names; 
  print STDERR "Processing $name\n"; 

  $my_graph->set( 
   x_label => 'Days', 
   y_label => 'CPU Utilization', 
   y_min_value => 0,
   y_max_value => 200,
   #title => 'Stacked Bars (incremental)', 
   cumulate => 1, 
   #overwrite => 1,
   x_label_position => 1/3,    
  #borderclrs => $my_graph->{dclrs}, 
   dclrs => [ qw( green dgreen  yellow dyellow ) ], 
   transparent => 0, 
   show_values => 1, 
   values_space => 1,
   bar_spacing => 2, 
   bargroup_spacing => 4, 
   accent_treshold => 200, 
 ); 
  $my_graph->set_values_font('/usr/lib/perl5/5.8.8/fonts/nimbus_roman_
+i.pfb', 8);
  $my_graph->set_legend( qw(E-Avg E-Max T-Avg T-Max)); 
  my $gd = $my_graph->plot(\@data); 
  open(IMG, '>',$name.'.gif') or die $!;
  binmode IMG;
  print IMG $gd->gif;
  close IMG;
}
[download]

Use undef in place of zero in your data

my @data = (  
['Mon','-','Tues','-','Wed','-'],
[10,undef,40,undef,80,undef], 
[30,undef,50,undef,90,undef], 
[undef,100,undef,60,undef,30], 
[undef,60,undef,70,undef,50],
);
[download]

poj

Hi Poj, that works for me, thanks. Now, I want 1 more graph with 3 stack bars. I have tried this by providing data in below format but its not working. Can u please help

my @data = ( 
['Mar1','Mar2','Mar3','Apr1','Apr2','Apr3','May1','May2','May3],
[1,0,2,0,4,0], 
[2,0,1,0,5,0], 
[0,3,0,3,0,6], 
[0,4,0,4,0,7],
[3,0,4,0,5,0],
[0,0,0,0,0,0],
);
[download]