This error shows up when trying to run your example.php file. Even with error reporting switched off and memory doubled it doesn't work:
1: Notice: Undefined property: svg_graph::$step in C:\wamp\www\svg\svg_graphics.php on line 227
2: Fatal error: Allowed memory size of 134217728 bytes exhausted (tried to allocate 6144 bytes) in C:\wamp\www\svg\svg_graphics.php(94) : runtime-created function on line 1
Mikhail - 2012-11-12 15:59:01 - In reply to message 1 from Ahmad Retha
Hi,
Thank's for testing, bug fixed.
It's appeared cause for testing of drawing graphics by dots i deleted
step from class, so I return it back and it's working now.