Fatal error: Uncaught Error: Undefined constant "STDERR" in /Library/WebServer/Documents/Morgan/common/php/phplot/test/compare_tests.php:29 Stack trace: #0 /Library/WebServer/Documents/Morgan/common/php/phplot/test/compare_tests.php(185): usage() #1 {main} thrown in /Library/WebServer/Documents/Morgan/common/php/phplot/test/compare_tests.php on line 29