Mac osx JpGraph Error:25049 Font file "/usr/share/fonts/truetype/arialbd.ttf" is not readable or does not exist.

Solution :
$ mkdir /path/to/jpgraph/fonts

#download arial.ttf, arialbd.ttf, ariali.ttf from internet, and move to /path/to/jpgraph/fonts

define('TTF_DIR','/path/to/jpgraph/fonts/');