lb=-5;
ub=5;
teix=0.05;
[X,Y] = meshgrid(lb:teix:ub,lb:teix:ub);
Z=-20*exp(-0.2*(0.5*(X.^2+Y.^2))^2)-exp(0.5*(cos(2*pi*X)+cos(2*pi*Y)))+22.71282;

% % mesh
% mesh(X,Y,Z)
% axis([-5 5 -5 5 18 25]);
% 
% title('unc#n2#Ackley');
% xlabel('x');
% ylabel('y');
% zlabel('z')


% %contour
% 
v=[18 19 19.5  20 20.5 21   ];
[c,h]=contour(X,Y,Z,v);
clabel(c,h);
title('unc#n2#Ackley');
xlabel('x');
ylabel('y');