Fatal error: Uncaught Error: Undefined constant "STDERR" in /var/www/html/tennisdata/PHPlot/src/contrib/color_range.test1.php:10 Stack trace: #0 /var/www/html/tennisdata/PHPlot/src/contrib/color_range.test1.php(24): usage() #1 {main} thrown in /var/www/html/tennisdata/PHPlot/src/contrib/color_range.test1.php on line 10