This QuickTime movie was created from SpiroChart by rotating the figure in one direction and the set of points within the figure in the opposite direction. Each frame representations a one-degree change in the cycle. (The value q was set to 2, the major radius to 0.0, the minor radius to 1.8, and the interval to 150 degrees. Phi and psi were each set to 90 degrees.)
If you set your QuickTime player to continue looping the movie, the motion of the figure will continue cycling smoothly. An interesting feature about the movie is that each vertex (corner) in the figure moves only along a line passing through the center.
You may be able to save considerable calculation time by reducing the size of the spreadsheet before making your own movies. (Be sure to save the original spreadsheet!) For any complete figure, the number of rows in the main part of the spreadsheet can be as low as the number of the lines in the figure, plus one. Look down the rightmost X and Y columns in the spreadsheet to determine where the pattern of numbers begins to repeat. You can eliminate all rows from that point downward. (The figure in this movie was generated by calculating only 13 points.)
