This chapter contains examples of plots produced with PHPlot.
Each of the following PHPlot examples shows an image, followed by the PHP script which produced that image. Each script is self-contained (needing only PHPlot), so you can copy it from this manual and run it with PHP to produce the image. Note that some of the scripts may require the latest version of PHPlot.
Note
The PHP CLI (command line interface), used to generate the examples here, never outputs HTTP headers. So it isn't necessary to use SetIsInline to suppress headers when using the CLI. This is a useful method you can use to debug and test your own PHPlot scripts without having to modify them for stand-alone use. Also, by using the CLI instead of a web server and browser, you can more readily see any error messages. Run your PHPlot scripts with the PHP CLI like this (using the ImageMagick display program to view the results):
$ php myscript.php > output.png $ display output.png
ImageMagick is available for several operating systems. There are many other image viewers for Linux and Linux-like systems, including qiv and geeqie.
This is a simple line plot with a single data set. Data type 'data-data' is used to include the X values (the years) in the data points.
Example 5.1. Line Plot
<?php
# PHPlot Example: Simple line graph
require_once 'phplot.php';
$data = array(
array('', 1800, 5), array('', 1810, 7), array('', 1820, 10),
array('', 1830, 13), array('', 1840, 17), array('', 1850, 23),
array('', 1860, 31), array('', 1870, 39), array('', 1880, 50),
array('', 1890, 63), array('', 1900, 76), array('', 1910, 92),
array('', 1920, 106), array('', 1930, 123), array('', 1940, 132),
array('', 1950, 151), array('', 1960, 179), array('', 1970, 203),
array('', 1980, 227), array('', 1990, 249), array('', 2000, 281),
);
$plot = new PHPlot(800, 600);
$plot->SetImageBorderType('plain');
$plot->SetPlotType('lines');
$plot->SetDataType('data-data');
$plot->SetDataValues($data);
# Main plot title:
$plot->SetTitle('US Population, in millions');
# Make sure Y axis starts at 0:
$plot->SetPlotAreaWorld(NULL, 0, NULL, NULL);
$plot->DrawGraph();