def generate_ratings():
"""Generate ratings from scratch based on all previous matches."""
elo_rating = EloRating()
matches = Match.objects.all().order_by('datetime')
for match in matches:
elo_rating.update_ratings(match.winner, match.loser)
PlayerRating.add_ratings(elo_rating)
def test_use_current_rating(self):
"""Test that the EloRating class can use current ratings."""
player = Player.objects.create(first_name='Bob', last_name='Hope')
test_rating = 1013
rated_player = PlayerRating.objects.create(player=player, rating=test_rating)
rating = EloRating(use_current_ratings=True)
self.assertEqual(test_rating, rating.get_rating(player))
def generate_ratings():
"""Generate ratings from all previous matches."""
PlayerRating.objects.all().delete()
matches = Match.objects.all().order_by('datetime')
elo_rating = EloRating()
for match in matches:
elo_rating.update_ratings(match.winner, match.loser)
for player, rating in elo_rating.ratings.items():
PlayerRating.objects.create(player=player, rating=rating)
def save(self, *args, **kwargs):
if self.id: # occurs when the match already exists and is being updated
super().save(*args, **kwargs)
PlayerRating.generate_ratings()
else: # occurs when it's a new match being added
super().save(*args, **kwargs)
elo_rating = EloRating(use_current_ratings=True)
elo_rating.update_ratings(self.winner, self.loser)
PlayerRating.add_ratings(elo_rating)
def test_new_ratings(self):
"""Test that new ratings are calculated properly."""
new_winner_rating, new_loser_rating = EloRating().calculate_new_ratings(
self.winner_rating,
self.loser_rating
)
self.assertEqual(new_winner_rating, self.new_winner_rating)
self.assertEqual(new_loser_rating, self.new_loser_rating)
def test_default_expected_score(self):
"""
Test that the default expected score is calculated properly.
With two players who have never played before, their default
expected score should be 0.5.
"""
default_expected_score = EloRating().get_expected_score('player1', 'player2')
self.assertEqual(default_expected_score, 0.5)
def test_rating_updates(self):
"""Test that the EloRating class updates and stores ratings."""
rating = EloRating()
rating.update_ratings(winner='player1', loser='player2')
winner_rating = rating.get_rating('player1')
loser_rating = rating.get_rating('player2')
expected_winner_rating = DEFAULT_ELO_RATING + DEFAULT_K_FACTOR * 0.5
expected_loser_rating = DEFAULT_ELO_RATING - DEFAULT_K_FACTOR * 0.5
self.assertEqual(winner_rating, expected_winner_rating)
self.assertEqual(loser_rating, expected_loser_rating)
def test_loser_expected_score(self):
"""Test that loser's expected score is calculated properly."""
loser_expected_score = EloRating.calculate_expected_score(
self.loser_rating, self.winner_rating)
self.assertEqual(loser_expected_score, self.loser_expected_score)
def test_default_rating(self):
"""Test that the default rating is correct."""
self.assertEqual(EloRating().get_rating('player'), DEFAULT_ELO_RATING)