run_trueskill.py

import trueskill


class Player(object):
    pass



def run(games, ratings, use_default_rating=False):
    """Update ratings based on games, and return new ratings

    GAMES is a list of dict objects, containing the following keys:

    players: a list of player identifiers
    rank:  a list of places in the game

    RATINGS is a dictionary of player identifiers matched with their
    (mu, sigma) rating.  RATINGS is modified in this function.

    If USE_DEFAULT_RATING is False, an error is thrown if a player
    in games is not in RATINGS.  Otherwise, the default mu and sigma
    are used.
    """

    trueskill.SetParameters(gamma = 0.0)
    for game in games:
        players = []
        for k in xrange(len(game['players'])):
            p = Player()
            p.id = game['players'][k]
            p.rank = game['rank'][k]

            if ratings.has_key(p.id):
                p.skill = ratings[p.id]
            elif use_default_rating:
                p.skill = (trueskill.INITIAL_MU, trueskill.INITIAL_SIGMA)
            else:
                raise Exception("Rating missing for: %s" % p.id)
            players.append(p)
        trueskill.AdjustPlayers(players)
        for p in players:
            ratings[p.id] = p.skill

if __name__ == "__main__":
    # examples
    def print_ratings(ratings):
        out = []
        for key in ratings.keys():
            mu, sigma = ratings[key]
            out.append((mu - 3 * sigma, key, mu, sigma))
        out.sort()
        out.reverse()
        for r, key, mu, sigma in out:
            print key, mu, sigma

    def example_1():
        games = [ { 'game_id': 0,
                    'map': 'random4',
                    'players': ['a', 'b', 'c', 'd'],
                    'rank': [0,1,2,3],
                    'score': [103, 153, 91, 167] } ]

        ratings = {}
        run(games, ratings, True)
        print_ratings(ratings)


    example_1()


    def example_1a():
        games = [ { 'game_id': 0,
                    'map': 'random4',
                    'players': ['a', 'b'],
                    'rank': [0,1]} ]

        ratings = {}
        run(games, ratings, True)
        print_ratings(ratings)        

    example_1a()

    print 
    def example_1b():
        games = [ { 'game_id': 0,
                    'map': 'random4',
                    'players': 'a b c d e f g h'.split(),
                    'rank': [0,1,2,3,4,5,6,7]} ]

        ratings = {}
        run(games, ratings, True)

        out = [(ratings[k], k) for k in ratings.keys()]
        out.sort()
        out.reverse()
        print_ratings(ratings)        

    example_1b()




    def example_2():
        games = [ { 'players': ['a', 'b', 'c', 'd'],
                    'rank': [0,1,2,3]},
                  { 'players': ['a', 'b', 'c', 'd'],
                    'rank': [0,1,2,3]},
                  { 'players': ['a', 'b', 'c', 'd'],
                    'rank': [0,1,2,3]}]

                  

        ratings = {'c': (25, 8), 'b': (23, 5), 'd': (28,5),
                    'a': (24, 6)}
        run(games, ratings, False)
        print_ratings(ratings)
    example_2()