why can't i plot this function? :(

I'm trying to plot this function. It gives me the following error.

Warning: Matrix is singular to working precision

I'm using Matlab 2011a.

G=@(x1,x2)(-(1+cos(12*sqrt(x1^2+x2^2)))/(0.5*(x1^2+x2^2)+2));

x=-5:.1:5; y=-5:.1:5; [x1 x2]=meshgrid(x,y);

mesh(x2,x1,G(x1,x2))

Answer 1

[David Sanchez]

Try it this way:

x = -5:.1:5; 
y = -5:.1:5; 
[x1 x2] = meshgrid(x,y);
G2 = -(1+cos(12.*sqrt(x1.^2+x2.^2)))./(0.5.*(x1.^2+x2.^2)+2);
mesh(x2,x1,G2)

[Hassan Dehghani]

tnx man, saved my day :)