[Gnuplot-info] Help with plotting 4D data

[Andy M. <and...@gm...>]

Hello,

I need a little help with a plot I am trying to produce.  It is
driving me crazy!  I'm keep thinking it is possible, but I'm not
completely sure.

So I have this particular function I am trying to plot.  I generate
data in the form (shorthand notation for my own ease):

s = 1:10
p = 1:30

[x,y,z] = f(s,p)

and I can fill up matricies any way I like to store the results.

I want to plot this ribbon is 3d space, I decided I didn't want to be
able to distinguish the s part (just leave that as a row), and have p
denoted by a change in colour.  So this surface twists like a ribbon,
starting at red, and finishing blue (or whatever)

What I did is create two data files, one for the surface position data
in the form:

x(s=1,p=1) y(s=1,p=1) z(s=1,p=1)
x(s=2,p=1) y(s=2,p=1) z(s=2,p=1)
x(s=3,p=1) y(s=3,p=1) z(s=3,p=1)
x(s=4,p=1) y(s=4,p=1) z(s=4,p=1)

x(s=1,p=2) y(s=1,p=2) z(s=1,p=2)
x(s=2,p=2) y(s=2,p=2) z(s=2,p=2)
x(s=3,p=2) y(s=3,p=2) z(s=3,p=2)
x(s=4,p=2) y(s=4,p=2) z(s=4,p=2)

etc

and another one the same for the colour data, but with the z column
replaced by p

I then get extremely stuck trying to plot this using splot with pm3d.

Am I fighting a losing battle? Or can someone help?

Thanks,

Andy.