Do you have a sample java code on how to plot x,y?

Hello:
I am new to the VisAD. The package seems to have powerful features.
Unfortunately, I have not had too much success in building a simple plot
routine.If anyone has a simple plot routine to plot x,y ( measurement vs
time...etc) I would really appreciate it.
Thanks

Henry Yeh

p.s. what is the difference between MathType and primative type ? Is
this an abstraction of primative type?