function h = surfplot(f,xmin,xmax);
%
% h = surfplot(f,xmin,xmax)
%
% It plots the function f(x) of two variables, where f is 
% an inline object.
% The first two components of vectors xmin and xmax 
% are used to define the fucntion.
%
% Example:
% xmin = [0 0];
% xmax = [10 10];
% fstr = 'sin(x(1))*cos(x(2))';  % INSERT YOUR FUNC HERE 
% f = inline(fstr,'x');
% Comment lines above to make the function useful
% Append any parameters to the function, if necessary.

PTNUM = 30;
x1 = linspace(xmin(1),xmax(1),PTNUM);
x2 = linspace(xmin(2),xmax(2),PTNUM);


for i=1:PTNUM,
     for j=1:PTNUM,
         Z(i,j) = f([x1(i),x2(j)]);         
         % if ZZ(j,i)<-0.018, ZZ(j,i) = NaN; % it's an example how to delete points         
     end;
end;
[X,Y] = meshgrid(x1,x2);
h = mesh(X,Y,Z);
return