bench 1 - Direct

f = @(x) x(1)/(x(2)+1e-15) + x(3)/(x(4)+1e-15) + x(5)/(x(6)+1e-15) + x(6)/(x(1)+1e-15);
Problem.f = f;
bounds = [zeros(1,6);ones(1,6)]';
opts.tol = 1e-9;
tic
[ret_minval,final_xatmin,history] = Direct...
   (Problem,bounds,opts);
toc
disp(ret_minval)