A multi-bar chart is a bar chart in which multiple data sets are represented by drawing the bars side by side in a cluster. The multi-bar layer is created by using XYChart.addBarLayer2 with the Side pre-defined constant.

This example employs two alternative colors as the plot area background. This is achieved by using PlotArea.setBackground.

In this example, a margin is configured at the top of the plot area for the legend keys. This is achieved by using Axis.setMargin.

[File: phpdemo/multibar.php".]

<?php require_once("../lib/phpchartdir.php"); #The data for the bar chart $data0 = array(100, 125, 245, 147, 67); $data1 = array(85, 156, 179, 211, 123); $data2 = array(97, 87, 56, 267, 157); $labels = array("Mon", "Tue", "Wed", "Thu", "Fri"); #Create a XYChart object of size 300 x 240 pixels $c = new XYChart(300, 240); #Add a title to the chart using 10 pt Arial font $c->addTitle(" Average Weekday Network Load", "", 10); #Set the plot area at (45, 25) and of size 239 x 180. Use two alternative #background colors (0xffffc0 and 0xffffe0) $plotAreaObj = $c->setPlotArea(45, 25, 239, 180); $plotAreaObj->setBackground(0xffffc0, 0xffffe0); #Add a legend box at (45, 20) using horizontal layout. Use 8 pt Arial font, with #transparent background $legendObj = $c->addLegend(45, 20, false, "", 8); $legendObj->setBackground(Transparent); #Add a title to the y-axis $c->yAxis->setTitle("Throughput (MBytes Per Hour)"); #Reserve 20 pixels at the top of the y-axis for the legend box $c->yAxis->setTopMargin(20); #Set the x axis labels $c->xAxis->setLabels($labels); #Add a multi-bar layer with 3 data sets $layer = $c->addBarLayer2(Side, 3); $layer->addDataSet($data0, 0xff8080, "Server #1"); $layer->addDataSet($data1, 0x80ff80, "Server #2"); $layer->addDataSet($data2, 0x8080ff, "Server #3"); #output the chart header("Content-type: image/png"); print($c->makeChart2(PNG)); ?>