A new tutorial has been posted to the Zend Developer Zone today looking at making scalable vector graphics with PHP and the hep of one of two charting packages - ezcGraph or SVGGraph (examples are provided for both).
Programmatically generating graphs and charts using SVG requires a deep understanding of the SVG specification and the various SVG primitives, as well as a fair amount of time for research, experimentation and debugging. Or, in other words, that's your entire weekend shot! Fortunately, help is at hand. There are a number of open-source PHP libraries that support SVG chart generation, and using them can significantly reduce the amount of work involved in adding this feature to a Web application.
He shows how to create simple images like bar, line and pie charts as well as adding in other things like a legend, custom titles and a sample where the user can define the sizes of a pie chart via some form input fields. Screenshots are included for all code examples to give you a better idea of the end result.