This is a Thin Bar Line Plot (thinbarline).
Example 5.16. Thin Bar Line
<?php # PHPlot Example: thinbarline plot require_once 'phplot.php'; # To get repeatable results with 'random' data: srand(1); # Make some noisy data: $data = array(); for ($i = 0; $i < 100; $i++) $data[] = array('', $i / 4.0 + 2.0 + rand(-20, 20) / 10.0); $plot = new PHPlot(800, 600); $plot->SetImageBorderType('plain'); $plot->SetPlotType('thinbarline'); $plot->SetDataType('text-data'); $plot->SetDataValues($data); # Main plot title: $plot->SetTitle('Noisy Data (thinbarline)'); $plot->DrawGraph();