- A sphere is specified in the control window, and its radius may
be changed by changing the variable R.

- A curve is displayed on the circle, and the curve is the
projection of the curve x(t) onto the sphere. This projected
curve is specified in the control window.

- A point along this image curve is a white sphere specified by
changing the value of t0.

- The tangent vector at this point T is displayed in red. The
normal vector
N is displayed in blue. The U vector is displayed in magenta.
- Readouts in the control window display the values of geodesic
curvature, geodesic torsion, and normal curvature at the white point
specified by t0.
- Readouts in the control window display the total geodesic
curvature, geodesic torsion, and normal curvature along the whole image
curve.
- The normal curvature along the whole curve is displayed in pink
in the "Kn(t)" window.
- The geodesic curvature along the whole curve is displayed in
orange in the "Kg(t)" window.
- The geodesic torsion along the whole curve is displayed in cyan
in the "Tg(t)" window.