Help with plotting in 3D

[xcamarox]

OK, I have very little knowledge of Matlab, but I know is very simple to plot with it, thats why my choice.

I have a function that has two variables and their result. I need to plot this function in terms of its variables and the result of them.

For example, say my function looks like this:

U (p,q) = ln(1/q) - cos (p) ... for example.

So we need to have p and q in the x , y axis and U as the z axis or whatever way to make it simpler. How would I do this?

I already have a random number generator to get the values of p and q. So I need to know how to code the plotting part of it.

How would you guys go about it?

TIA!

 

[dontthinktwice]

I haven't used Matlab in a while, but something like this should work (for 100 points of p between 1 and 15, and for 50 points of q between 10 and 20):

p = linspace(1,15,100)
q = linspace(10,20,50)

for x = 1:length(p),
U[:,x] = ln(1./q) - cos(p[x])
end

plot3d(p,q,U)