Using surf for plotting function

I have a function f(i,j). How to plot a 3D graph (like surf) for f(i,j) vs x(i) vs y(j) ?

I have to plot it against two different variables x and y . f is not a direct function of x and y.

For example: Take f(i,j) = i*j [ for i=1:4,j=1:3 ]

x = [5,6,7,10]; y=[2,-3,4]; Now I have to plot f(i,j) vs x(i) vs y(j)

Answer 1

[Image Analyst]

Do you mean like this:

x = [5,6,7,10]; 
y=[2,-3,4];
[X, Y] = meshgrid(x,y);
f = X .* Y
surf(f);

[chaos]

No, f=1,2,3,4,5,6,7,8,9,10,11,12. I wanted to plot f vs x vs y