elementary cellular automata

This code takes the rule number for an elementary cellular automaton as input, and then runs the CA from a random seed, rendering the result. The seed comprises 600 random bits taken from rule 30. Its length, when accounting for scale, is greater than the window width; this helps keep pathological edge effects outside the visible frame. The screenshot at left shows an execution of the famous rule 110.

wolfram's random generator

Despite its fundamental simplicity, the rule 30 elementary CA is conjectured to generate a purely random sequence along its center column. It reputably excels at many statistical tests of randomness, and Mathematica includes it as a choice of RNG.

For my own conviction, it was enough to find that the expression sum (take 80 $ rands 5000) `div` 80 produces 2525.

Since each random bit requires computing a full cell generation, this algorithm quickly slows down. I assume more pragmatic implementations solve this by perhaps re-seeding the automaton after some number of iterations.