def compute_optimal_ranking_set(self, fold, input_cutoff, output_cutoff):
hits_by_user = self.hits_by_fold[fold]
recommended_to_user = self._compute_recommended_in_fold(
fold, input_cutoff)
matrix = np.ndarray((len(recommended_to_user), output_cutoff))
user_ids = []
for user_index, (user_id, recommended_items) in enumerate(
recommended_to_user.items()):
user_ids.append(user_id)
rank = 0
for item_id in recommended_items:
if item_id in hits_by_user[user_id]:
matrix[user_index, rank] = item_id
rank += 1
if rank == output_cutoff:
break
else:
for item_id in recommended_items:
if item_id not in hits_by_user[user_id]:
matrix[user_index, rank] = item_id
rank += 1
if rank == output_cutoff:
break
ranking_set_id = dataset_io.RankingSetId(fold, 'MAPOracle')
ranking_set = dataset_io.RankingSet(ranking_set_id, matrix, user_ids)
return ranking_set
def test_compute_optimal_ranking_set(self):
ranking_set_u1 = dataset_io.RankingSet(id=dataset_io.RankingSetId(
'u1', 'Alg'),
matrix=np.array([[1, 2, 3]]),
user_ids=[1])
ranking_set_by_id = {
ranking_set_u1.id: ranking_set_u1,
}
rating_set = dataset_io.RatingSet(fold='u1')
rating_set.base = pd.DataFrame.from_records(
columns=['user_id', 'item_id', 'rating'], data=[])
rating_set_by_fold = {'u1': rating_set}
oracle = eild_oracle.EILDOracle(ranking_set_by_id, rating_set_by_fold)
distance_matrix = np.array([[0, 0.5, 0.2], [0.5, 0, 0.9],
[0.2, 0.9, 0]])
oracle.distances_by_fold = {'u1': (distance_matrix, [1, 2, 3])}
optimal_ranking_set = oracle.compute_optimal_ranking_set(
'u1', input_cutoff=3, output_cutoff=2)
self.assertEqual([1], optimal_ranking_set.user_ids)
matrix = optimal_ranking_set.matrix
self.assertEqual([2, 3], list(matrix[0, :]))
def test_compute_optimal_ranking_set(self):
ranking_set_u1 = dataset_io.RankingSet(
id=dataset_io.RankingSetId('u1', 'Alg'),
matrix=np.array([[1, 2, 3, 4], [5, 6, 7, 8]]),
user_ids=[1, 2])
ranking_set_by_id = {
ranking_set_u1.id: ranking_set_u1,
}
rating_set = dataset_io.RatingSet(fold='u1')
rating_set.base = pd.DataFrame.from_records(
columns=['user_id', 'item_id', 'rating'], data=[])
rating_set_by_fold = {'u1': rating_set}
oracle = epc_oracle.EPCOracle(ranking_set_by_id, rating_set_by_fold)
oracle.popularity_by_fold = {'u1': {
1: 1., 2: 0.25, 3: 0.5, 4: 0.75,
5: 0.8, 6: 0.3, 7: 0.6, 8: 0.01
}}
optimal_ranking_set = oracle.compute_optimal_ranking_set(
'u1', input_cutoff=4, output_cutoff=3)
self.assertEqual([1, 2], optimal_ranking_set.user_ids)
matrix = optimal_ranking_set.matrix
self.assertEqual([2, 3, 4], list(matrix[0, :]))
self.assertEqual([8, 6, 7], list(matrix[1, :]))
def test_ranking_with_single_item(self):
ranking_matrix = np.array([[1]])
ranking_set = dataset_io.RankingSet(id=dataset_io.RankingSetId(
'u1', 'Alg'),
matrix=ranking_matrix,
user_ids=[])
self.assertAlmostEqual(0, self.eild.compute(ranking_set))
def test_ranking_with_item_not_in_ratings(self):
item_ids = [1]
distance_matrix = np.array([[1]])
self.eild.distances_by_fold = {'u1': (distance_matrix, item_ids)}
ranking_matrix = np.array([[1, 2]])
ranking_set = dataset_io.RankingSet(id=dataset_io.RankingSetId(
'u1', 'Alg'),
matrix=ranking_matrix,
user_ids=[])
self.assertAlmostEqual(0, self.eild.compute(ranking_set))
def test_returns_mean_for_many_rankings(self):
hits_by_user = {1: {1}, 2: {}}
self.map.hits_by_fold = {'u1': hits_by_user}
ranking_matrix = np.array([[1], [1]])
ranking_set = dataset_io.RankingSet(id=dataset_io.RankingSetId(
'u1', 'Alg'),
matrix=ranking_matrix,
user_ids=[1, 2])
self.assertAlmostEqual(0.5, self.map.compute(ranking_set))
def test_ranking_with_single_miss(self):
hits_by_user = {1: {1}}
self.map.hits_by_fold = {'u1': hits_by_user}
ranking_matrix = np.array([[1]])
ranking_set = dataset_io.RankingSet(id=dataset_io.RankingSetId(
'u1', 'Alg'),
matrix=ranking_matrix,
user_ids=[1])
self.assertAlmostEqual(1, self.map.compute(ranking_set))
def test_single_item(self):
ranking_matrix = np.array([[1]])
ranking_set = dataset_io.RankingSet(
id=dataset_io.RankingSetId('u1', 'Alg'),
matrix=ranking_matrix,
user_ids=[])
self.epc.popularity_by_fold = {'u1': pd.Series({1: 1})}
value = self.epc.compute(ranking_set)
self.assertAlmostEqual(0, value)
def test_returns_mean_for_many_rankings(self):
ranking_matrix = np.array([[1], [2]])
ranking_set = dataset_io.RankingSet(
id=dataset_io.RankingSetId('u1', 'Alg'),
matrix=ranking_matrix,
user_ids=[])
self.epc.popularity_by_fold = {'u1': pd.Series({1: 0.5, 2: 0.3})}
value = self.epc.compute(ranking_set)
expected_value = (0.5 + 0.7) / 2
self.assertAlmostEqual(expected_value, value)
def test_many_items(self):
ranking_matrix = np.array([[1, 2, 3]])
ranking_set = dataset_io.RankingSet(
id=dataset_io.RankingSetId('u1', 'Alg'),
matrix=ranking_matrix,
user_ids=[])
self.epc.popularity_by_fold = {'u1': pd.Series({1: 0.5, 2: 0.3, 3: 0.1})}
value = self.epc.compute(ranking_set)
expected_value = (0.5 + 0.7 * 0.85 + 0.9 * 0.85**2) / (1 + 0.85 + 0.85**2)
self.assertAlmostEqual(expected_value, value)
def test_complex_ranking_with_missing_hits(self):
hits_by_user = {1: {1, 3, 4}}
self.map.hits_by_fold = {'u1': hits_by_user}
ranking_matrix = np.array([[1, 2, 5, 3]])
ranking_set = dataset_io.RankingSet(id=dataset_io.RankingSetId(
'u1', 'Alg'),
matrix=ranking_matrix,
user_ids=[1])
expected_map = (1 + 2 / 4) / 3
self.assertAlmostEqual(expected_map, self.map.compute(ranking_set))
def test_compute_recommended_in_fold(self):
ranking_set_u1 = dataset_io.RankingSet(
id=dataset_io.RankingSetId('u1', 'Alg'),
matrix=np.array([[1, 2, 3, 4], [5, 6, 7, 8]]),
user_ids=[1, 2])
ranking_set_u2 = dataset_io.RankingSet(
id=dataset_io.RankingSetId('u2', 'Alg'),
matrix=np.array([[1, 2, 3, 4], [5, 6, 7, 8]]),
user_ids=[2, 3])
ranking_set_by_id = {
ranking_set_u1.id: ranking_set_u1,
ranking_set_u2.id: ranking_set_u2,
}
oracle = oracle_utils.Oracle(
ranking_set_by_id, rating_set_by_fold={})
recommended_in_fold = oracle._compute_recommended_in_fold('u1', cutoff=3)
expected = {1: {1, 2, 3}, 2: {5, 6, 7}}
self.assertDictEqual(expected, recommended_in_fold)
def compute_optimal_ranking_set(self, fold, input_cutoff, output_cutoff):
distance_matrix, item_ids = self.distances_by_fold[fold]
mean_distance_by_item = pd.Series(distance_matrix.sum(axis=0), index=item_ids)
recommended_to_user = self._compute_recommended_in_fold(fold, input_cutoff)
matrix = np.ndarray((len(recommended_to_user), output_cutoff))
user_ids = []
for i, (user_id, recommended_to_user) in enumerate(recommended_to_user.items()):
user_ids.append(user_id)
matrix[i, :] = heapq.nlargest(output_cutoff, recommended_to_user,
lambda i: mean_distance_by_item.get(i, 0.))
ranking_set_id = dataset_io.RankingSetId(fold, 'EILDOracle')
ranking_set = dataset_io.RankingSet(ranking_set_id, matrix, user_ids)
return ranking_set
def compute_optimal_ranking_set(self, fold, input_cutoff, output_cutoff):
popularity_by_item = self.popularity_by_fold[fold]
recommended_to_user = self._compute_recommended_in_fold(
fold, input_cutoff)
matrix = np.ndarray((len(recommended_to_user), output_cutoff))
user_ids = []
for i, (user_id,
recommended_to_user) in enumerate(recommended_to_user.items()):
user_ids.append(user_id)
matrix[i, :] = heapq.nsmallest(
output_cutoff, recommended_to_user,
lambda i: popularity_by_item.get(i, 99999999.))
ranking_set_id = dataset_io.RankingSetId(fold, 'EPCOracle')
ranking_set = dataset_io.RankingSet(ranking_set_id, matrix, user_ids)
return ranking_set
def test_compute_optimal_ranking_set(self):
ranking_set_u1 = dataset_io.RankingSet(id=dataset_io.RankingSetId(
'u1', 'Alg'),
matrix=np.array([[1, 2, 3, 4],
[5, 6, 7, 8]]),
user_ids=[1, 2])
ranking_set_by_id = {
ranking_set_u1.id: ranking_set_u1,
}
rating_set = dataset_io.RatingSet(fold='u1')
rating_set.base = pd.DataFrame.from_records(
columns=['user_id', 'item_id', 'rating'], data=[(4, 1, 5)])
rating_set.test = pd.DataFrame.from_records(
columns=['user_id', 'item_id', 'rating'],
data=[
(1, 3, 5),
(1, 2, 5),
(2, 1, 5),
(2, 8, 5),
])
rating_set_by_fold = {'u1': rating_set}
oracle = map_oracle.MAPOracle(ranking_set_by_id, rating_set_by_fold)
optimal_ranking_set = oracle.compute_optimal_ranking_set(
'u1', input_cutoff=4, output_cutoff=3)
self.assertEqual([1, 2], optimal_ranking_set.user_ids)
matrix = optimal_ranking_set.matrix
self.assertEqual(3, len(matrix[0, :]))
self.assertSetEqual({2, 3}, set(matrix[0, 0:2]))
self.assertTrue(set(matrix[0, 2:]).issubset({1, 4}))
self.assertEqual(3, len(matrix[1, :]))
self.assertSetEqual({8}, set(matrix[1, 0:1]))
self.assertTrue(set(matrix[1, 1:]).issubset({5, 6, 7}))
def test_many_items(self):
item_ids = [1, 2, 3]
distance_matrix = np.array([
[1, 2 / math.sqrt(6), 1 / math.sqrt(3)],
[2 / math.sqrt(6), 1, 1 / math.sqrt(2)],
[1 / math.sqrt(3), 1 / math.sqrt(2), 1],
])
self.eild.distances_by_fold = {'u1': (distance_matrix, item_ids)}
ranking_matrix = np.array([[1, 2, 3]])
ranking_set = dataset_io.RankingSet(id=dataset_io.RankingSetId(
'u1', 'Alg'),
matrix=ranking_matrix,
user_ids=[])
eild_k0 = (2 / math.sqrt(6) + 0.85 / math.sqrt(3)) / 1.85
eild_k1 = (2 / math.sqrt(6) + 1 / math.sqrt(2)) / 2
eild_k2 = (1 / math.sqrt(3) + 1 / math.sqrt(2)) / 2
expected_eild = (eild_k0 + eild_k1 * 0.85 +
eild_k2 * 0.85**2) / (1 + 0.85 + 0.85**2)
self.assertAlmostEqual(expected_eild, self.eild.compute(ranking_set))
def test_returns_mean_for_many_rankings(self):
item_ids = [1, 2, 3]
distance_matrix = np.array([
[1, 2 / math.sqrt(6), 1 / math.sqrt(3)],
[2 / math.sqrt(6), 1, 1 / math.sqrt(2)],
[1 / math.sqrt(3), 1 / math.sqrt(2), 1],
])
self.eild.distances_by_fold = {'u1': (distance_matrix, item_ids)}
ranking_matrix = np.array([[1, 2], [2, 3]])
ranking_set = dataset_io.RankingSet(id=dataset_io.RankingSetId(
'u1', 'Alg'),
matrix=ranking_matrix,
user_ids=[])
eild_k0_u0 = eild_k1_u0 = 2 / math.sqrt(6)
eild_u0 = (eild_k0_u0 + eild_k1_u0 * 0.85) / (1 + 0.85)
eild_k0_u1 = eild_k1_u1 = 1 / math.sqrt(2)
eild_u1 = (eild_k0_u1 + eild_k1_u1 * 0.85) / (1 + 0.85)
expected_eild = (eild_u0 + eild_u1) / 2
self.assertAlmostEqual(expected_eild, self.eild.compute(ranking_set))
