sinus_on_cilinder(7)

f(5,2.5,20);
function []=f(R,h,N)
    fi=0:0.01:2*pi;
    x=R*cos(fi);
    y=R*sin(fi);
    z=h*sin(N*fi)+h;
    plot3(x,y,z);
    grid on;
end