Hi, I'd like to draw your attention to this bug report:
https://sourceforge.net/tracker/index.php?func=detail&aid=1934732&group_id=4933&atid=104933
If anyone can take a look, that would be great.
Couple of notes. (1) probably you'll need to change plot3d(f(...), ...) to
plot3d('f(...), ...) (insert quote mark as noted in comment on bug report).
(2) change [ngrid, 860, 580] to something smaller to make it go faster.
Btw the plot attached to the bug report is really nice!
Robert Dodier