Iterated Prisoner's Dilemma

The iterated prisoner's dilemma (IPD) game has long been studied in game theory, economics, programming, decision theory and other fields. It is a 2-player scenario where each player must decide to either 'cooperate' or 'defect' in a sequence of games, and their respective choices determine the relative success or failure of each player. Will you cooperate with your opponent or look to steal all the points for yourself?

This code runs a tournament among two or more players. Each player may submit as many "personalities" as they wish. Each personality submitted by each player plays the IPD game against all personalities submitted by all other players. Results are then plotted and outputted.

An example has already been set up in this submission among 3 example players and a number of simple sample personalties for each player. To create your own players and personalites, simply swap out the player directories and example functions. To run the example,
>> IPDshell

For more detail, specific rules and instructions for creating your own personalities,
>> help IPDshell

For more information on the prisoner's dilemma see:
http://plato.stanford.edu/entries/prisoner-dilemma/