Cliff Reiter, With J: The Hodgepodge Machine, APL Quote Quad, 34 4 (2004) 2-7.

The Hodgepodge machine is a multi-state automaton originally designed to simulate an oscillating chemical reaction. We implement a real-valued version in J. The rule is often described in terms of healthy, infected and ill states. Healthy cells have a value of zero and may become infected (or ill) if a sufficient number of their neighbors are ill or infected; infected cells have values strictly in between 0 and 1 and typically tend toward becoming more infected (larger) or ill; an ill cell has value 1 and becomes healthy (but not immune) at the next step. The automata utilize several parameters and many behaviors occur, including oscillating spiral waves.

See also: · Preprint and associated materials [Hodgepodge Machine]