MATLAB: Plotting a function…

MATLABplotting

I have the following function that I would like to plot.

    Gamma = atand((Y)/(X));

Whats the best way to preform this task. Y and X will vary from 0 to 40.

Thanks,

[X,Y] = meshgrid(0:.1:40, 0:.1,40);
surf(X, Y, atand(Y ./ X));

Two options:

1. Set Z > 4 to NaN:

[X,Y] = meshgrid(-5:.2:5);                                
Z = -0.15*sin(X).*(X) + 0.2*(Y.^2) +3 ;
Z(Z>4) = NaN;
figure
surf(X,Y,Z)

2. Use a zlim cutoff:

[X,Y] = meshgrid(-5:.2:5);                                
Z = -0.15*sin(X).*(X) + 0.2*(Y.^2) +3 ;
figure
surf(X,Y,Z)
zlim([min(zlim) 4])

There may also be other possibiloities.

[X,Y] = meshgrid(-5:.2:5);
Z = Y .* sin(X) - X .* cos(Y);
surf(X,Y,Z)