# Homework Help: Matlab 3d plotting

1. Dec 27, 2009

### shogun61

f(x,y)=$$\frac{(x+y)}{(y/100+x/50)}$$
how can i plot this function with matlab in the region restricted between y=-2x and x=0 lines?

i wanted to plot that the second region of the cartesian coordinate
x=-1:0.1:0;
y=-2*x+eps , eps is very small
[X,Y]=meshgrid(x,y);
z=(X+Y)./(X/100+Y/50);
surf(z)

but it is not what i want.is there another way to plot this?

2. Dec 27, 2009

### Wo0p

Why so hard? Just plot regular, then remove the region you don't want

Edit: What I mean is, you can create masks and use them to selectively crop out undesirable portions of your graph (e.g. the singularities that occur along the y=-2x line) Note that your viewport will still be rectangular

x = -2:0.1:2;
y = -2:0.1:2;
[X,Y] = meshgrid(x,y);
Mu = X < 0;
Ml = Y > -2*X;
surf(X,Y,double(z.*Mu.*Ml));

Hope this helps.

Last edited: Dec 27, 2009