Fatal error: Uncaught Error: Undefined constant "STDERR" in /var/www/html/tennisdata/PHPlot/phplotdocs/examples/histogram.php:47 Stack trace: #0 /var/www/html/tennisdata/PHPlot/phplotdocs/examples/histogram.php(73): get_histogram() #1 /var/www/html/tennisdata/PHPlot/phplotdocs/examples/histogram.php(107): plot_histogram() #2 {main} thrown in /var/www/html/tennisdata/PHPlot/phplotdocs/examples/histogram.php on line 47