[R] stepfuns: R^2 -> R

[Roger Koenker]

Does anyone have any suggestions on perspective plotting of piecewise constant functions?
Ideally, I would like something like plot.stepfun for functions that are piecewise
constant on polygons.   Even pointers to non-R strategies would be welcome at this stage.

url:	www.econ.uiuc.edu	Roger Koenker		Dept. of Economics UCL,
email	rkoenker at uiuc.edu	Department of Economics Drayton House,
vox: 	217-333-4558		University of Illinois	30 Gordon St,
fax:   	217-244-6678		Champaign, IL 61820	London,WC1H 0AX, UK