m routines for making plots.

Hi.

I am a developer of Oplot,http://oplot.sourceforge.net.
Oplot simulates set,get, line, image, surface mechanisms,  which you can 
find in a program, which name we don't mention.

I need algorithms how to make a contour plot using the plot-command.
I am also interested in patch, piechart, bar, errorbar and so on.

If you have some algorithms, that I can use, please don't hesitate.

Thanks in advance.

Cheers,

Ole J.