Copyright &copyr; 2013 Bart Massey

This small program is a demo written largely in my Fall 2013 CS 441/541 Intro AI class at Portland State University. It contains a (probably borked) model of the inverted pendulum problem, together with a GA-based optimizer that tries to position the cart in a completely open-loop fashion to maximize the time that the pendulum will stay balanced while the cart remains on the track bounds.

The genome is just a list of changes to cart position over time. New instances are produced by crossover taking an arbitrary prefix of one parent to an arbitrary suffix of another. Selection is by rank-ordering. Mutation is by replacement of a single cart position in the genome.

There are a few arguments that can be discovered by reading the code. The code also contains some hard-coded constants.

Some scripts are available for running the program and plotting stats with gnuplot.

• Use try.sh with a given population and number of generations to get files showing behavior over time. This script requires /usr/bin/time, available from the time package in Debian.

• Use show.sh to plot a graph of performance over generations. This script requires gnuplot, available in Debian.

There is also an X version that displays some graphics. It requires pkg-config, libcairo-dev and libxcb-util0-dev. Say make xinvpend. I don't remember how it works.

This program is licensed under the "MIT License". Please see the file COPYING in this distribution for license terms.