Why doesn't supsmooth yield a result?

[Raiko]

Hello folks,

I've got data here of a surface roughness measurement. I'm trying several smoothing functions in order to get the main features of the surface. medsmooth, ksmooth work, supsmooth however doesn't work. Any idea what I'm doing wrong?

I'm running "real" mathcad; i.e. MC15 on a 64 byte, Win7 machine. A file with data is attached.

Raiko

[AlanStevens]

supsmooth works for me with Kr, but not with Ref.

Alan

[AndyWesterman · Accepted solution]

I looked at the error message - the elements must be in ascending order.

A small program comparing 2 elements at a time shows 184 entries where 2 adjacent lines have the same value & I suspect it is this that supsmooth is complaining about.

Why the others don't ... who knows.

[AlanStevens]

Well done Andy, you are quite right!  I've just removed the repeated x-values in Ref and supsmooth works ok on what is left.

Alan

[Raiko]

Thanks Andy, removing repeated values did the trick.

Raiko