这应该工作：

ezmesh('cos(u)*(1+sin(v)*cos(u))-(sin(2.*v))*(sin(u)/2)',...
       'sin(u)*((1+sin(v)*cos(u))-(sin(2.*v))*(sin(u)/2))',...
       'sin(u)*sin(v)+(cos(u)*(sin(2.*v))/2)',[-pi,3,-3,pi]);

axis([-4 4 -4 4 -4 4])