i managed to re-code the logic of showing the text scaffolds and picture. One problem solved.
It seems there is a bug i can't work around it.
Only for p = -1.8 , f = 1.8, a strange drawing appears.
The rest of the values seems to work well.
any suggestion how to make the bug disappear?[img]http://www.phy.ntnu.edu.tw/ntnujava/index.php?action=dlattach;topic=1167.0;attach=1198;image[/img]