% Example of mesh function for plotting surfaces
% Author: F. P. Schloerb

% define regular x,y grid
x = -100:100;
y = -100:100;

% compute the value of "z" for each point in x,y grid
% this is sin(r)/r or "sinc" function
for i=1:length(x)
    for j=1:length(y)
        r = sqrt(x(i)*x(i)+y(j)*y(j));
        if(r == 0)
            z(i,j) = 1; % note special handling for r=0!
        else
            z(i,j) = sin(0.2*r)/(0.2*r);
        end
    end
end

% call the mesh function to plot the surface
mesh(x,y,z)

% label the plot
xlabel('X')
ylabel('Y')
zlabel('Z')
title('Mesh plot example - sinc function')