Again, short post. This php code:

<?php
session_start();
require_once "/srv/www/lib/pChart/class/pDraw.class.php";
require_once "/srv/www/lib/pChart/class/pImage.class.php";
require_once "/srv/www/lib/pChart/class/pData.class.php";

$squareSeries = array();
$cubeSeries = array();
$fourthSeries = array();

for ($i = 0; $i <= 4; $i++){ 	$squareSeries[$i] = pow($i,2); 	$cubeSeries[$i] = pow($i,3); 	$fourthSeries[$i] = pow($i, 4); } $myPowersData = new pData(); $myPowersData -> addPoints($squareSeries,"Square");
$myPowersData -> addPoints($cubeSeries,"Cube");
$myPowersData -> addPoints($fourthSeries,"Fourth");

$myPowersData-> setPalette("Square",
	array("R" => 240, "G" => 16, "B" => 16, "Alpha" => 100));
$myPowersData-> setPalette("Cube",
	array("R" => 16, "G" => 240, "B" => 16, "Alpha" => 100));
$myPowersData-> setPalette("Forth",
	array("R" => 16, "G" => 16, "B" => 240, "Alpha" => 100));

$myPowersImage = new pImage(500,300, $myPowersData);
$myPowersImage -> setFontProperties(array(
	"FontName" => "/srv/www/lib/pChart/fonts/verdana.ttf",
	"FontSize" => 12));

$myPowersImage->setGraphArea(40,40, 460,260);
$myPowersImage->drawScale();

$myPowersImage->drawLineChart();
header("Content-Type: image/png");
$myPowersImage->Render(null);

will produce this graph:

I learned this using this resource:

http://phpmaster.com/charting-with-pchart/