One of many excellent code repositories for PHP sniplets is at
px.sklar.com. The "Graphics" section features the
following chart-related items. I've added sample output each time.
"Bar charts" by Afan Ottenheimer. Similar in nature to what is described in this tutorial. Deals with
negative values as well.
"Pie chart class" by Bjørn Bond. Because of some redundancy in the code, it could be
made much smaller. Some display glitches (background color showing through between slices) that could be
made to disappear by refining the draw methods. Recommended if you are going to use it as is,
without major changes.
"»±ýÍ¼" by Xiaohu He is based on the previous "Pie chart class" in spite of its apparent unicode
title, but much smaller. Suffers from the same display glitches. Due to its small size, it is probably
better suited as a starting point if you want to build your own script.
I hope that this article provided you with enough ideas to get you started.
Don't hesitate to contact me with your remarks and suggestions.