How to plot a constant function in 3D?

Hi guys,

I am a newbie. I want to plot:

f(x,y)={1/4 if -1 <= x <= 1 and -1 <= y <= -2x+1; 0 otherwise on x,y : [-2,2]

I have tried with plot3 and mesh but I failed. Any suggestions? Thanks.

Answer 1

[Walter Roberson]

[X, Y] = ndgrid(linspace(-2,2,100));
F = zeros(size(X));
F(X >= -1 & SOMETHING_GOES_HERE) = 1/4;
surf(X, Y, F);