use of mapw command

[Dave Zirl]

We are trying to use the "mapw" command to transform a selected position
(X,Y) on the screen into world coordinates(x,y,z).   We have no problem
getting the X,Y coordinates without calling mapw, but can't seem to make 
mapw return the correct line.
	
We think the problem lies in the multiple transformations(rotations,
zooms, translations) that the system can undergo and that these
transformations somehow distort the view

Any help would be greatly appreciated.

Please respond directly via e-mail to:
dmz at rutile.rutgers.edu

Thanks in advance

David Zirl
Rutgers University
Department of Ceramics
(dmz at rutile.rutgers.edu)