Waterfall Chart

perldemo\waterfall.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;

# 4 data points to represent the cash flow for the Q1 - Q4
my $data = [230, 140, 220, 330, 150];

# We want to plot a waterfall chart showing the 4 quarters as well as the total
my $labels = ["Product 1", "Product 2", "Product 3", "Product 4", "Product 5", "Total"];

# The top side of the bars in a waterfall chart is the accumulated data. We use the ChartDirector
# ArrayMath utility to accumulate the data. The "total" is handled by inserting a zero point at the
# end before accumulation (after accumulation it will become the total).
my $boxTop = new ArrayMath($data)->insert2(0, 1)->acc()->result();

# The botom side of the bars is just the top side of the previous bar. So we shifted the top side
# data to obtain the bottom side data.
my $boxBottom = new ArrayMath($boxTop)->shift(1, 0)->result();

# The last point (total) is different. Its bottom side is always 0.
$boxBottom->[scalar(@$boxBottom) - 1] = 0;

# Create a XYChart object of size 500 x 280 pixels. Set background color to light blue (ccccff),
# with 1 pixel 3D border effect.
my $c = new XYChart(500, 290, 0xccccff, 0x000000, 1);

# Add a title to the chart using 13 points Arial Bold Itatic font, with white (ffffff) text on a
# deep blue (0x80) background
$c->addTitle("Product Revenue - Year 2004", "Arial Bold Italic", 13, 0xffffff)->setBackground(
    0x000080);

# Set the plotarea at (55, 50) and of size 430 x 215 pixels. Use alternative white/grey background.
$c->setPlotArea(55, 45, 430, 215, 0xffffff, 0xeeeeee);

# Set the labels on the x axis using Arial Bold font
$c->xAxis()->setLabels($labels)->setFontStyle("Arial Bold");

# Set the x-axis ticks and grid lines to be between the bars
$c->xAxis()->setTickOffset(0.5);

# Use Arial Bold as the y axis label font
$c->yAxis()->setLabelStyle("Arial Bold");

# Add a title to the y axis
$c->yAxis()->setTitle("USD (in millions)");

# Add a multi-color box-whisker layer to represent the waterfall bars
my $layer = $c->addBoxWhiskerLayer2($boxTop, $boxBottom);

# Put data labels on the bars to show the cash flow using Arial Bold font
$layer->setDataLabelFormat("{={top}-{bottom}}M");
$layer->setDataLabelStyle("Arial Bold")->setAlignment($perlchartdir::Center);

# Output the chart
$c->makeChart("waterfall.png");