ChartDirector 7.0 (PHP Edition)

Discrete Heat Map




This example demonstrates the basic steps in creating a discrete heat map.

A discrete heat map consists of rectangular cells in a grid of which the cell color depends on its data value.

Source Code Listing

[File: phpdemo/discreteheatmap.php]
<?php require_once("../lib/phpchartdir.php"); # The x-axis and y-axis labels $xLabels = array("A", "B", "C", "D", "E", "F", "G", "H", "I", "J"); $yLabels = array("0", "1", "2", "3", "4", "5", "6", "7", "8", "9"); # Random data for the 10 x 10 cells $r = new RanSeries(2); $zData = $r->get2DSeries(count($xLabels), count($yLabels), 0, 100); # Create an XYChart object of size 520 x 470 pixels. $c = new XYChart(520, 470); # Set the plotarea at (50, 30) and of size 400 x 400 pixels. $p = $c->setPlotArea(50, 30, 400, 400); # Create a discrete heat map with 10 x 10 cells $layer = $c->addDiscreteHeatMapLayer($zData, count($xLabels)); # Set the x-axis labels. Use 8pt 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. $c->xAxis->setLabels($xLabels); $c->xAxis->setLabelStyle("Arial Bold", 8); $c->xAxis->setColors(Transparent, TextColor); $c->xAxis->setLabelOffset(0.5); $c->xAxis->setTitle("X Axis Title Placeholder", "Arial Bold", 12); # Set the y-axis labels. Use 8pt 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. $c->yAxis->setLabels($yLabels); $c->yAxis->setLabelStyle("Arial Bold", 8); $c->yAxis->setColors(Transparent, TextColor); $c->yAxis->setLabelOffset(0.5); $c->yAxis->setTitle("Y Axis Title Placeholder", "Arial Bold", 12); # Position the color axis 20 pixels to the right of the plot area and of the same height as the plot # area. Put the labels on the right side of the color axis. Use 8pt Arial Bold font for the labels. $cAxis = $layer->setColorAxis($p->getRightX() + 20, $p->getTopY(), TopLeft, $p->getHeight(), Right); $cAxis->setLabelStyle("Arial Bold", 8); # Output the chart $viewer = new WebChartViewer("chart1"); $viewer->setChart($c, SVG); # Include tool tip for the chart $viewer->setImageMap($c->getHTMLImageMap("", "", "title='<*cdml*>({xLabel}, {yLabel}) = {z|2}'")); ?> <!DOCTYPE html> <html> <head> <title>Discrete Heat Map</title> <!-- Include ChartDirector Javascript Library to support chart interactions --> <script type="text/javascript" src="cdjcv.js"></script> </head> <body style="margin:5px 0px 0px 5px"> <div style="font:bold 18pt verdana;"> Discrete Heat Map </div> <hr style="border:solid 1px #000080; background:#000080" /> <div style="font:10pt verdana; margin-bottom:1.5em"> <a href="viewsource.php?file=<?=basename(__FILE__)?>">View Chart Source Code</a> </div> <!-- ****** Here is the chart image ****** --> <?php echo $viewer->renderHTML(); ?> </body> </html>