I imploved under two classes.

1. org.jfree.chart.axis.AxisSpace
2. org.jfree.chart.plot.XYPlot

I commet at imploved point with two types under.

for example.

-type1: large implovement

  I put new sorce code in '//<--' and '//-->'

  //<---
  // The plot area infomation in real space.
  // 2005.12.19 (add.nabe)

  .... watanabe implove or add code ....

  //--> (:END signature)

-type2: short implovement
  I comment it likes under following.

  /** The domain axis space of temporary used.
  * add.nabe 21.10.2005*/
  private AxisSpace tempDomainAxisSpace;

THANKS David Gilbert and Thomas Morgner.