Find minimum and maximum of a two variable function on fixed interval

Hi every body I have this function below and I would calculated the minimum and maximum of this, and also ploting the min/max values.

How I can write their code?

 [x,y]=meshgrid(0:0.1:pi,0:0.1:2*pi) 
a=77.2; b=36.2; c=12.9;
E=100;
U=-E.^2*(a.*sin(x).^2.*cos(y).^2+b.*sin(x).^2.*sin(y).^2+c.*cos(x).^2);

Regards

Answer 1

[jonas]

Just take the max/min over the desired dimension. For example:

max(U,[],1) %max row-wise
max(U,[],2) %max column-wise

You can plot like this:

plot(x(1,:),max(U,[],1),...
    x(1,:),min(U,[],1),...
    y(:,1),max(U,[],2),...
    y(:,1),min(U,[],2))