Spiro was written by Peter C. Davidson in 2008 (or thereabouts).

I hope you enjoy it.


HOW TO USE

-Load the program onto your TI-83/84 Plus
-Open “SPIRO” in the Program menu or in a file manager such as MirageOS (MirageOS can run it while archived).
-Input a turn angle from 1-360 degrees, then press Enter.
-Input an upper step length (e.g. inputting 7 will cause the steps to cycle from 1 to 7 then repeat), then press Enter.
-Watch your spirolateral come to life!

WHILE IN DRAWING MODE

-Use the arrow keys to move around
-Use the plus and minus keys to zoom
-Press Clear to start over

NOTES

-I think I programmed this opposite to how spirolaterals are normally defined. For example, a turn angle of 5 degrees does not create a 5 degree angle between the two segments (a very sharp turn), but rather deflects the drawing direction by 5 degrees (a very slight turn). You can get around this by subtracting your desired angle from 360 and using that number instead.


Feel free to share this program and/or create derivative works, but please credit me and provide my email address (peterd17@gmail.com) or website (petercdavidson.com).

Thank you!

Peter C. Davidson
peterd17@gmail.com
petercdavidson.com