Hello Mike,

If you can make it work at the "on error" that Smath 5346 does not have
the Smath community will heritate a nice piece of work that I heritated
from Paul W. [Mathcad 11 Collaboratory]. If there is a way to make it
work in 5346, I will most appreciate. The R, G, B are all in the collapsed
areas, nothing to download. The coding stops at the empty place holders.

Thanks for your kindly cooperation, good luck.

Jean

Rotate Image.sm (431 KiB) downloaded 70 time(s).

Wrote

rotate() tries to get fourth col of a matrix having only two cols:
trace.sm (100 KiB) downloaded 64 time(s).

Actually, I didn't try to understand the algo yet, so I have no clue how to improve it.

Edit:
in the original algo, there's no line like

s:augment(col(s,2),col(s,4))

Removing it gives another error: j becomes -14, and this index isn't OK as a matrix col.

Edit 2: here it is, should work for 5346: Rotate Image.sm (407 KiB) downloaded 72 time(s). (updated for 2x speed using eval()).

Edit: and here is the colored version (great thanks to Alex Melnik): Rotate Image+color.sm (414 KiB) downloaded 67 time(s).