Polar Line Chart

This example demonstrates a polar line chart, completed with data symbols and data labels.

The grid lines in this example is circular (instead of polygonal as is in Simple Radar Chart). This is configured using PolarChart.setGridStyle.
The angular scale in this example is set to 0 - 360, with spokes every 30 units. This is by using AngularAxis.setLinearScale.
The two lines in this example is added using PolarChart.addLineLayer with angular coordinates of the points provided by PolarLayer.setAngles.
The data symbols are enabled using PolarLayer.setDataSymbol.
The data labels are configured using PolarLayer.setDataLabelFormat to consist of the radial and angular coordinates.
The data label background colors and 3D borders are configured using PolarLayer.setDataLabelStyle and Box.setBackground.
Note that the blue line in this example is a closed loop (the default), while the red is not a loop. This is configured by using PolarLineLayer.setCloseLoop.

[File: phpdemo/polarline.php]

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

# The data for the chart
$data0 = array(90, 25, 40, 55, 68, 44, 79, 85, 50);
$angles0 = array(15, 60, 110, 180, 230, 260, 260, 310, 340);

$data1 = array(80, 91, 66, 80, 92, 87);
$angles1 = array(40, 65, 88, 110, 150, 200);

# Create a PolarChart object of size 460 x 500 pixels, with a grey (e0e0e0)
# background and 1 pixel 3D border
$c = new PolarChart(460, 500, 0xe0e0e0, 0x000000, 1);

# Add a title to the chart at the top left corner using 15pts Arial Bold Italic font.
# Use a wood pattern as the title background.
$textBoxObj = $c->addTitle("Polar Line Chart Demo", "arialbi.ttf", 15);
$textBoxObj->setBackground($c->patternColor(dirname(__FILE__)."/wood.png"));

# Set center of plot area at (230, 280) with radius 180 pixels, and white (ffffff)
# background.
$c->setPlotArea(230, 280, 180, 0xffffff);

# Set the grid style to circular grid, with grids below the chart layers
$c->setGridStyle(false, false);

# Add a legend box at top-center of plot area (230, 35) using horizontal layout. Use
# 10 pts Arial Bold font, with 1 pixel 3D border effect.
$b = $c->addLegend(230, 35, false, "arialbd.ttf", 9);
$b->setAlignment(TopCenter);
$b->setBackground(Transparent, Transparent, 1);

# Set angular axis as 0 - 360, with a spoke every 30 units
$c->angularAxis->setLinearScale(0, 360, 30);

# Add a blue (0xff) line layer to the chart using (data0, angle0)
$layer0 = $c->addLineLayer($data0, 0x0000ff, "Close Loop Line");
$layer0->setAngles($angles0);

# Set the line width to 2 pixels
$layer0->setLineWidth(2);

# Use 11 pixel triangle symbols for the data points
$layer0->setDataSymbol(TriangleSymbol, 11);

# Enable data label and set its format
$layer0->setDataLabelFormat("({value},{angle})");

# Set the data label text box with light blue (0x9999ff) backgruond color and 1 pixel
# 3D border effect
$textBoxObj = $layer0->setDataLabelStyle();
$textBoxObj->setBackground(0x9999ff, Transparent, 1);

# Add a red (0xff0000) line layer to the chart using (data1, angle1)
$layer1 = $c->addLineLayer($data1, 0xff0000, "Open Loop Line");
$layer1->setAngles($angles1);

# Set the line width to 2 pixels
$layer1->setLineWidth(2);

# Use 11 pixel diamond symbols for the data points
$layer1->setDataSymbol(DiamondSymbol, 11);

# Set the line to open loop
$layer1->setCloseLoop(false);

# Enable data label and set its format
$layer1->setDataLabelFormat("({value},{angle})");

# Set the data label text box with light red (0xff9999) backgruond color and 1 pixel
# 3D border effect
$textBoxObj = $layer1->setDataLabelStyle();
$textBoxObj->setBackground(0xff9999, Transparent, 1);

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