Reference

  JpGraph - PHP Graph Creating Library[2004-05-10-9]
  http://www.aditus.nu/jpgraph/
  PHPLOT
  http://www.phplot.com/
  Welcome to PHPlot - PHPlot 5.0 へようこそ (邦訳)
  http://tec-tech.org/phplot5/doc/index-j.php
  SourceForge - PHPLOT
  http://sourceforge.net/projects/phplot/