@acer 

Hi, there doesn't seem to be any files in the links....?

I am using Maple 17.0: I am unable to upgrade etc as this is provided on a site license by my university.

However, I seem to have got the plot for that data set working - I must have made an error previously. 

I am now trying to apply the same approach to another data set (I have a lot of them) which uses the same idea. I

Many thanks for all of your assistance!

@acer 

Hi acer - thanks for that detailed answer. 

However, I am still having issues and I don't get why...

I tried copying the commands you have used exactly: splitting the matrix manually gives me a surface similar to the first picture in my original post. Trying to use the lowess just gives me an error of 'incorrect number of coordinates in points data'. I am doing something wrong here?

thanks for your help

@Carl Love 

for the ion to always be on the cooridntate axes, either x,y or z always has to be zero. 

Whilst this is isnitally the case, in step 8, non of them are zero, and the ion is no longer on the coordinate axes: 

The ion starts at (0,0,0). It moves to (0.05,0,0). Then to (0.1,0,0) etc until (1.0,0,0).

I then start again at (0,0.05,0). (0.05,0.05,0.0), then (0.1,0.05,0.0) etc until (1.0,0.05,0.0).

I then move to (0,0.1,0.0). (0.05,0.1,0.0), etc until (1.0,0.1,0.0). 

etc. until (1.0,1.0,0.0)

I then restart at (0,0,0.05). (0.05,0,0.05) then (0.1,0,0.05) etc. until (1,0,0.05).

I then start again at (0,0.05,005). (0.05,0.05,0.05), then (0.1,0.05,0.05) etc until (1.0,0.05,0.05).

I then move to (0,0.1,0.05). (0.05,0.1,0.05), etc until (1.0,0.1,0.05).

etc. until (1.0,1.0,0.05)

etc. until (1.0,1.0,1.0)