Fatal error: Uncaught Error: Class "Graph" not found in D:\HTTP\htdocs\gincludes\jpgraph-3.5.0b1-pro\src\jpgraph_matrix.php:22 Stack trace: #0 {main} thrown in D:\HTTP\htdocs\gincludes\jpgraph-3.5.0b1-pro\src\jpgraph_matrix.php on line 22