The problem may have something to do with the structure
of your data. Does the following example work for you
in displaying all 3 values for the legend?
use GD::Graph::hbars;
use strict;
use warnings;
my @data = (
['Jan', 'Feb', 'Mar', 'Apr'],
[5, 7, 9, 6],
[2, 2, 3, 1],
[4, 4, 6, 3],
);
my @legend = qw(maximum minimum average);
my $graph = GD::Graph::hbars->new(600, 500);
$graph->set (
x_label => 'Month',
y_label => 'Value',
title => 'GD::Graph::hbars example',
bar_spacing => 6,
show_values => 1,
legend_placement => 'BL',
legend_spacing => 5,
show_values => 1,
legend_marker_height => 12,
dclrs => [ qw(orange cyan lred) ],
) or warn $graph->error;
$graph->set_legend(@legend);
my $gd = $graph->plot(\@data) or warn $graph->error;
open(IMG, ">graph.png") or die $!;
binmode IMG;
print IMG $gd->png;
close IMG;
