Status: dormant; 2004
In 2004, I wrote a small MATLAB program that animates geometric inversion of the plane, bringing arbitrary polar-parametric curves along. If you have MATLAB or a compatible system, try it out! As of 2020-08-31, I tested that this still works on Octave after almost 16 years, though it isn't as pretty out of the box.
| Description | File | Size | Modification time |
|---|---|---|---|
| Inversion animation package | inversion-animation.tar.bz2 | 2013 | 2006-01-15 02:38:48 +0000 |
| Inversion animation package | inversion-animation.zip | 3000 | 2006-01-15 02:39:30 +0000 |
MATT MCCUTCHEN'S INVERSION ANIMATION
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To use this software:
1. Launch MATLAB and put the folder with the four included .m files on your MATLAB path.
2. At the command prompt, type:
inversionAnimationDemo
to see the demo: inversion of a line and a circle.
3. If you want to invert your own curves, type:
help inversionAnimation
for information on how to use the underlying ``inversionAnimation'' routine.
For example, this command inverts a parabola with a focus at the origin, giving a cardioid:
inversionAnimation(3, (0:pi/12:2*pi)', {inline('[1./(1+cos(t)),t]','t')})
A little MATLAB experience helps here.
4. If you want to invert a tic-tac-toe board, type:
invertATicTacToeBoard
You can also invert it with Xs and Os on it by supplying a 3x3 matrix of 1s
(X), -1s (O), and 0s (blank). Play inverted tic-tac-toe; it's fun!