Simple Area Chart

This example demonstrates the basic steps in creating area charts.

Create an XYChart object using XYChart.XYChart.
Specify the plot area of the chart using XYChart.setPlotArea. The plot area is the rectangle bounded by the x and y axes. You should leave some margin on the outside of the plot area for axis labels, chart titles, etc.
Specify the labels on the x-axis using Axis.setLabels.
An area chart may contain many points and therefore many x-axis labels. In this example, Axis.setLabelStep is used to specify showing only a subset of the labels on the x-axis to avoid over-crowding.
Add an area layer and specify the data for the area using XYChart.addAreaLayer.
Generate the chart using BaseChart.makeChart2.

[File: phpdemo/simplearea.php]

<?php
require_once("../lib/phpchartdir.php");

# The data for the area chart
$data = array(30, 28, 40, 55, 75, 68, 54, 60, 50, 62, 75, 65, 75, 89, 60, 55, 53, 35,
    50, 66, 56, 48, 52, 65, 62);

# The labels for the area chart
$labels = array("0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12",
    "13", "14", "15", "16", "17", "18", "19", "20", "21", "22", "23", "24");

# Create a XYChart object of size 250 x 250 pixels
$c = new XYChart(250, 250);

# Set the plotarea at (30, 20) and of size 200 x 200 pixels
$c->setPlotArea(30, 20, 200, 200);

# Add an area chart layer using the given data
$c->addAreaLayer($data);

# Set the labels on the x axis.
$c->xAxis->setLabels($labels);

# Display 1 out of 3 labels on the x-axis.
$c->xAxis->setLabelStep(3);

# Output the chart
header("Content-type: image/png");
print($c->makeChart2(PNG));
?>