source: trunk/xgraph/jpgraph/Examples/windrose_ex4.php

<?php
require_once ('jpgraph/jpgraph.php');
require_once ('jpgraph/jpgraph_windrose.php');

// Data can be specified using both ordinal index of the axis
// as well as the direction label
$data = array(
    0 => array(1,1,2.5,4),
    1 => array(3,4,1,4),
    3 => array(2,7,4,4,3),
    5 => array(2,7,1,2));

// First create a new windrose graph with a title
$graph = new WindroseGraph(400,400);

// Setup title
$graph->title->Set('Windrose example 4');
$graph->title->SetFont(FF_VERDANA,FS_BOLD,12);
$graph->title->SetColor('navy');

// Create the windrose plot.
$wp = new WindrosePlot($data);

// Adjust the font and font color for scale labels
$wp->scale->SetFont(FF_TIMES,FS_NORMAL,11);
$wp->scale->SetFontColor('navy');

// Set the diameter and position for plot
$wp->SetSize(190);

// Set the size of the innermost center circle to 40% of the plot size
// Note that we can have the automatic "Zero" sum appear in our custom text
$wp->SetZCircleSize(0.38);
$wp->scale->SetZeroLabel("Station 12\n(Calm %d%%)");

// Adjust color and font for center circle text
$wp->scale->SetZFont(FF_ARIAL,FS_NORMAL,9);
$wp->scale->SetZFontColor('darkgreen');

// Adjust the font and font color for compass directions
$wp->SetFont(FF_ARIAL,FS_NORMAL,10);
$wp->SetFontColor('darkgreen');

// Adjust the margin to the compass directions
$wp->SetLabelMargin(50);

// Adjust grid colors
$wp->SetGridColor('silver','blue');

// Add (m/s) text to legend
$wp->legend->SetText('(m/s)');
$wp->legend->SetMargin(20,5);

// Add and send back to client
$graph->Add($wp);
$graph->Stroke();
?>