This example demonstrates adding symbols and custom legend keys to the discrete heat map.
perldemo\heatmapcellsymbols.pl
#!/usr/bin/perl
# The ChartDirector for Perl module is assumed to be in "../lib"
use File::Basename;
use lib (dirname($0)."/../lib") =~ /(.*)/;
use perlchartdir;
# The x-axis and y-axis labels
my $xLabels = ["Alpha", "Beta", "Gamma", "Delta", "Epsilon", "Zeta", "Eta", "Theta", "Iota", "Kappa"
];
my $yLabels = ["Ant", "Bear", "Cat", "Dog", "Elephant", "Fox", "Goat", "Horse", "Insect",
"Jellyfish"];
# Random data for the 10 x 10 cells
my $rand = new RanSeries(2);
my $zData = $rand->getSeries(scalar(@$xLabels) * scalar(@$yLabels), 0, 10);
# The coordinates for the first set of scatter symbols
my $symbolX = [2.5, 6.5, 3.5, 8.5];
my $symbolY = [4.5, 7.5, 9.5, 8.5];
# The coordinates for the second set of scatter symbols
my $symbol2X = [6.5, 3.5, 7.5, 1.5];
my $symbol2Y = [0.5, 7.5, 3.5, 2.5];
# Create an XYChart object of size 600 x 500 pixels.
my $c = new XYChart(600, 500);
# Set the plotarea at (80, 80) and of size 400 x 400 pixels. Set the background, border, and grid
# lines to transparent.
my $p = $c->setPlotArea(80, 80, 400, 400, -1, -1, $perlchartdir::Transparent,
$perlchartdir::Transparent);
# Add the first set of scatter symbols. Use grey (0x555555) cross shape symbols.
$c->addScatterLayer($symbolX, $symbolY, "Disputed", perlchartdir::Cross2Shape(0.2), 15, 0x555555);
# Add the first set of scatter symbols. Use yellow (0xffff66) star shape symbols.
$c->addScatterLayer($symbol2X, $symbol2Y, "Audited", perlchartdir::StarShape(5), 19, 0xffff66);
# Create a discrete heat map with 10 x 10 cells
my $layer = $c->addDiscreteHeatMapLayer($zData, scalar(@$xLabels));
# Set the x-axis labels. Use 10pt Arial Bold font rotated by 90 degrees. Set axis stem to
# transparent, so only the labels are visible. Set 0.5 offset to position the labels in between the
# grid lines. Position the x-axis at the top of the chart.
$c->xAxis()->setLabels($xLabels);
$c->xAxis()->setLabelStyle("Arial Bold", 10, $perlchartdir::TextColor, 90);
$c->xAxis()->setColors($perlchartdir::Transparent, $perlchartdir::TextColor);
$c->xAxis()->setLabelOffset(0.5);
$c->setXAxisOnTop();
# Set the y-axis labels. Use 10pt Arial Bold font. Set axis stem to transparent, so only the labels
# are visible. Set 0.5 offset to position the labels in between the grid lines. Reverse the y-axis
# so that the labels are flowing top-down instead of bottom-up.
$c->yAxis()->setLabels($yLabels);
$c->yAxis()->setLabelStyle("Arial Bold", 10);
$c->yAxis()->setColors($perlchartdir::Transparent, $perlchartdir::TextColor);
$c->yAxis()->setLabelOffset(0.5);
$c->yAxis()->setReverse();
# Set the color stops and scale
my $colorScale = [0, 0xff0000, 1, 0xff8800, 3, 0x4488cc, 7, 0x99ccff, 9, 0x00ff00, 10];
my $colorLabels = ["Poor", "Fair", "Good", "Very Good", "Excellent"];
$layer->colorAxis()->setColorScale($colorScale);
# Position the legend box 20 pixels to the right of the plot area. Use 10pt Arial Bold font. Set the
# key icon size to 15 x 15 pixels. Set vertical key spacing to 8 pixels.
my $b = $c->addLegend($p->getRightX() + 20, $p->getTopY(), 1, "Arial Bold", 10);
$b->setBackground($perlchartdir::Transparent, $perlchartdir::Transparent);
$b->setKeySize(15, 15);
$b->setKeySpacing(0, 8);
# Add the color scale label to the legend box
for(my $i = scalar(@$colorLabels) - 1; $i >= 0; --$i) {
$b->addKey($colorLabels->[$i], int($colorScale->[$i * 2 + 1]));
}
# Output the chart
$c->makeChart("heatmapcellsymbols.png");
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