Eigenvalue decomposition: 16 random 2x2 matrices

Fatal error: Uncaught Error: Class 'Matrix' not found in /var/www/html/inc/classes/PHPExcel/Shared/JAMA/examples/benchmark.php:52 Stack trace: #0 /var/www/html/inc/classes/PHPExcel/Shared/JAMA/examples/benchmark.php(189): Benchmark->runEig(2, 16) #1 {main} thrown in /var/www/html/inc/classes/PHPExcel/Shared/JAMA/examples/benchmark.php on line 52