Torus 1

x=linspace(0,2*%pi,40);
y=linspace(0,2*%pi,20)';
factor=1.5+cos(y);
X=factor*cos(x);
Y=factor*sin(x);
Z=sin(y)*ones(x)+ ones(y)*cos(2*x);
plot3d2(X,Y,Z);