create matrices or 3-D arrays

x = -1:0.1:1;
y = -1:0.1:1;

[X,Y] = meshgrid(x,y);

for i=1:size(X,1)
  for j=1:size(X,2)
    Z(i,j) = sinc(2*%pi*X(i,j)*Y(i,j));
  end
end

f = scf();
surf(X,Y,Z)
f.color_map = jetcolormap(32);