ChartDirector Ver 3.0 (Perl Edition)

Positive Negative Bar




This example is achieved by using zones and zone colors.

Source Code Listing

[File: perldemo/posnegbar.pl] (The CGI version is available as "perldemo_cgi/posnegbar.pl".)
#!/usr/bin/perl use perlchartdir; #The data for the bar chart my $data = [-6.3, 2.3, 0.7, -3.4, 2.2, -2.9, -0.1, -0.1, 3.3, 6.2, 4.3, 1.6]; #The labels for the bar chart my $labels = ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]; #Create a XYChart object of size 500 x 320 pixels my $c = new XYChart(500, 320); #Add a title to the chart using Arial Bold Italic font $c->addTitle("Productivity Change - Year 2001", "arialbi.ttf"); #Set the plotarea at (50, 30) and of size 400 x 250 pixels $c->setPlotArea(50, 30, 400, 250); #Add a bar layer to the chart my $layer = $c->addBarLayer2(); #Add a data set to the bar using a y zone color. The color is configured to be #orange (0xff6600) below zero, and blue (0x6666ff) above zero. $layer->addDataSet($data, $layer->yZoneColor(0, 0xff6600, 0x6666ff)); #Add labels to the top of the bar using 8 pt Arial Bold font. The font color is #configured to be red (0xcc3300) below zero, and blue (0x3333ff) above zero. $layer->setAggregateLabelStyle("arialbd.ttf", 8, $layer->yZoneColor(0, 0xcc3300, 0x3333ff)); #Set the labels on the x axis and use Arial Bold as the label font $c->xAxis()->setLabels($labels)->setFontStyle("arialbd.ttf"); #Draw the y axis on the right of the plot area $c->setYAxisOnRight(1); #Use Arial Bold as the y axis label font $c->yAxis()->setLabelStyle("arialbd.ttf"); #Add a title to the y axis $c->yAxis()->setTitle("Percentage"); #Add a light blue (0xccccff) zone for positive part of the plot area $c->yAxis()->addZone(0, 9999, 0xccccff); #Add a pink (0xffffcc) zone for negative part of the plot area $c->yAxis()->addZone(-9999, 0, 0xffcccc); #output the chart $c->makeChart("posnegbar.png")