"""
Module description:
"""
__version__ = '0.3.1'
__author__ = 'Vito Walter Anelli, Claudio Pomo'
__email__ = 'vitowalter.anelli@poliba.it, claudio.pomo@poliba.it'
import pickle
import time
from elliot.recommender.recommender_utils_mixin import RecMixin
from elliot.utils.write import store_recommendation
from elliot.recommender.base_recommender_model import BaseRecommenderModel
from elliot.recommender.knn.item_knn.item_knn_similarity import Similarity
from elliot.recommender.knn.item_knn.aiolli_ferrari import AiolliSimilarity
from elliot.recommender.base_recommender_model import init_charger
[docs]class ItemKNN(RecMixin, BaseRecommenderModel):
r"""
Amazon.com recommendations: item-to-item collaborative filtering
For further details, please refer to the `paper <http://ieeexplore.ieee.org/document/1167344/>`_
Args:
neighbors: Number of item neighbors
similarity: Similarity function
implementation: Implementation type ('aiolli', 'classical')
To include the recommendation model, add it to the config file adopting the following pattern:
.. code:: yaml
models:
ItemKNN:
meta:
save_recs: True
neighbors: 40
similarity: cosine
implementation: aiolli
"""
@init_charger
def __init__(self, data, config, params, *args, **kwargs):
self._params_list = [
("_num_neighbors", "neighbors", "nn", 40, int, None),
("_similarity", "similarity", "sim", "cosine", None, None),
("_implementation", "implementation", "imp", "standard", None, None),
("_implicit", "implicit", "bin", False, None, None),
("_shrink", "shrink", "shrink", 0, None, None),
("_normalize", "normalize", "norm", True, None, None),
("_asymmetric_alpha", "asymmetric_alpha", "asymalpha", False, None, lambda x: x if x else ""),
("_tversky_alpha", "tversky_alpha", "tvalpha", False, None, lambda x: x if x else ""),
("_tversky_beta", "tversky_beta", "tvbeta", False, None, lambda x: x if x else ""),
("_row_weights", "row_weights", "rweights", None, None, lambda x: x if x else "")
]
self.autoset_params()
self._ratings = self._data.train_dict
if self._implementation == "aiolli":
self._model = AiolliSimilarity(data=self._data,
maxk=self._num_neighbors,
shrink=self._shrink,
similarity=self._similarity,
implicit=self._implicit,
normalize=self._normalize,
asymmetric_alpha=self._asymmetric_alpha,
tversky_alpha=self._tversky_alpha,
tversky_beta=self._tversky_beta,
row_weights=self._row_weights)
else:
if (not self._normalize) or (self._asymmetric_alpha) or (self._tversky_alpha) or (self._tversky_beta) or (self._row_weights) or (self._shrink):
self.logger.info("Options normalize, asymmetric_alpha, tversky_alpha, tversky_beta, row_weights are ignored with standard implementation. Try with implementation: aiolli")
self._model = Similarity(data=self._data, num_neighbors=self._num_neighbors, similarity=self._similarity, implicit=self._implicit)
[docs] def get_single_recommendation(self, mask, k, *args):
return {u: self._model.get_user_recs(u, mask, k) for u in self._ratings.keys()}
[docs] def get_recommendations(self, k: int = 10):
predictions_top_k_val = {}
predictions_top_k_test = {}
recs_val, recs_test = self.process_protocol(k)
predictions_top_k_val.update(recs_val)
predictions_top_k_test.update(recs_test)
return predictions_top_k_val, predictions_top_k_test
@property
def name(self):
return f"ItemKNN_{self.get_params_shortcut()}"
[docs] def train(self):
if self._restore:
return self.restore_weights()
start = time.time()
self._model.initialize()
end = time.time()
print(f"The similarity computation has taken: {end - start}")
print(f"Transactions: {self._data.transactions}")
self.evaluate()
# best_metric_value = 0
#
# recs = self.get_recommendations(self.evaluator.get_needed_recommendations())
# result_dict = self.evaluator.eval(recs)
# self._results.append(result_dict)
# print(f'Finished')
#
# if self._results[-1][self._validation_k]["val_results"][self._validation_metric] > best_metric_value:
# print("******************************************")
# if self._save_weights:
# with open(self._saving_filepath, "wb") as f:
# pickle.dump(self._model.get_model_state(), f)
# if self._save_recs:
# store_recommendation(recs, self._config.path_output_rec_result + f"{self.name}.tsv")