This example contains three zones in the plot area background, colored as red, green and blue.

The red region is the background color of the plot area, configured using PolarChart.setPlotArea.

The green and blue region are actually spline area layers. The data points are equally spaced and at equal distances from the center. By joining the data points with spline curves, the resulting area will look circles.

[File: phpdemo/polarzones.php".]

<?php require_once("../lib/phpchartdir.php"); #The data for the chart $data0 = array(22, 27.4, 22, 17, 13, 27, 26, 20.2, 23, 28, 27, 24); #The circular data points used to represent the zones $zone0 = array(15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15); $zone1 = array(25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25); #The labels for the chart $labels = array("Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sept", "Oct", "Nov", "Dec"); #Create a PolarChart object of size 400 x 420 pixels $c = new PolarChart(400, 420); #Set background color to a 2 pixel pattern color, with a black border and 1 #pixel 3D border effect $c->setBackground($c->patternColor(array(0xffffff, 0xe0e0e0), 2), 0, 1); #Add a title to the chart using 16 pts Arial Bold Italic font. The title text is #white (0xffffff) on 2 pixel pattern background $titleObj = $c->addTitle("Chemical Concentration", "arialbi.ttf", 16, 0xffffff); $titleObj->setBackground($c->patternColor(array(0x0, 0x80), 2)); #Set center of plot area at (200, 240) with radius 145 pixels. Set background #color to 0xffcccc $c->setPlotArea(200, 240, 145, 0xffcccc); #Set the grid style to circular grid $c->setGridStyle(false); #Set the radial axis label format $radialAxisObj = $c->radialAxis(); $radialAxisObj->setLabelFormat("{value} ppm"); #Add a legend box at (200, 30) top center aligned, using 9 pts Arial Bold font. #with a black border, and 1 pixel 3D border effect. $legendBox = $c->addLegend(200, 30, false, "arialbd.ttf", 9); $legendBox->setAlignment(TopCenter); #Add a legend key to represent the red (0xffcccc) zone $legendBox->addKey("Over-Absorp", 0xffcccc); #Add a spline area layer using circular data to represent the green (0xaaffaa) #and blue (0xccccff) zones $c->addSplineAreaLayer($zone1, 0xaaffaa, "Normal"); $c->addSplineAreaLayer($zone0, 0xccccff, "Under-Absorp"); #Add a blue (0x80) spline line layer with line width set to 3 pixels $splineLineLayerObj = $c->addSplineLineLayer($data0, 0x80); $splineLineLayerObj->setLineWidth(3); #Set the labels to the angular axis as spokes. Set the font size to 10 pts #fonts. $angularAxisObj = $c->angularAxis(); $labelsObj = $angularAxisObj->setLabels($labels); $labelsObj->setFontSize(10); #output the chart header("Content-type: image/png"); print($c->makeChart2(PNG)); ?>