Gencols

gencols
Homepage	Click here
Purpose	Search program to enumerate and test collisions and other pattern interactions
Created by	Paul Callahan
Platform	C

gencols is an open source C program that enumerates and tests collisions and other pattern interactions in Life, developed by Paul Callahan in 1994.

The program works by generating interactions between pairs of patterns within a range of user-determined parameters, and filters the output for "interesting" objects (those with special properties). This includes, but is by no means limited to, collisions occurring between pairs of gliders. The program combines fast Life simulation code exploiting sparsity and bit parallelism with an enumerative search for collisions. It employs a sophisticated approach to choosing which collisions to enumerate, beyond the obvious approach of overlaying patterns at all sufficiently close translations from each other. For example, it eliminates almost all collisions that cannot be attained by patterns that are initially separated from each other.

In 2010, Paul Tooke modified gencols to work with isotropic non-totalistic rules.

External links

• Program to search for collisions in Conway's Life (description) at Paul Callahan's Page of Conway's Life Miscellany
• gencols on GitHub
• gencols: techniques (discussion thread) at the ConwayLife.com forums