Variables and functions:
- “D”: tracing variable
- spirograph:
- “M”: radius of the track wheel (set to “r” to be inline with ellipse)
- “N”: radius of rotating wheel
- “H”: total number of holes of rotating wheel
- “P”: pen hole chosen
- “d”: distance from pen to edge
- “f”: parametric function for wheel “N” inside of “M”
- “g”: parametric function for wheel “N” outside of “M”
- ellipse:
- “A”: semimajor axis of ellipse track
- “B”: semiminor axis of ellipse track
- “c”: eccentricity of ellipse
- “p”: perimeter of ellipse
- “r”: radius of a wheel with the same perimeter as the ellipse
- “h”: parametric function representing the offset by using an ellipse track
