This demo includes a single graphical display window that displays the
cylindrical helix X(t) = (a*cos(t),a*sin(t),bt). You can change t0,
a, b, and X(t) and choose whether or not to show
the entire curve and the position vector X(t0) in the
control window. You can also choose whether or not to show the cylinder
of radius a with the z-axis as its axis of symmetry, which is the
cylinder on which X(t) lies.