This is a simple pie chart showing the data type 'text-data'. When you use this data type with pie charts, the first entry in each record (a label) is ignored; the sum of all the second entries equals the relative size of the first slice, the sum of the third entries is the second slice, etc. So this pie has 4 slices, of relative size 250, 200, 350, and 200.
Data type 'data-data' is similar, except the first two entries in each record (label and X value for other plot types) is ignored.
Example 5.9. Pie Chart, text-data

<?php
# PHPlot Example: Pie/text-data
require_once 'phplot.php';
$data = array(
  array('', 100, 100, 200, 100),
  array('', 150, 100, 150, 100),
);
$plot = new PHPlot(800,600);
$plot->SetImageBorderType('plain');
$plot->SetDataType('text-data');
$plot->SetDataValues($data);
$plot->SetPlotType('pie');
$plot->DrawGraph();