Source code for cornac.models.global_avg.recom_global_avg
# Copyright 2018 The Cornac Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# ============================================================================
import numpy as np
from ..recommender import Recommender
from ...exception import ScoreException
[docs]
class GlobalAvg(Recommender):
"""Global Average baseline for rating prediction. Rating predictions equal to average rating
of training data (not personalized).
Parameters
----------
name: string, default: 'GlobalAvg'
The name of the recommender model.
"""
def __init__(self, name="GlobalAvg"):
super().__init__(name=name, trainable=False)
[docs]
def score(self, user_idx, item_idx=None):
"""Predict the scores/ratings of a user for an item.
Parameters
----------
user_idx: int, required
The index of the user for whom to perform score prediction.
item_idx: int, optional, default: None
The index of the item for which to perform score prediction.
If None, scores for all known items will be returned.
Returns
-------
res : A scalar or a Numpy array
Relative scores that the user gives to the item or to all known items
"""
if item_idx is None:
return np.full(self.num_items, self.global_mean)
else:
return self.global_mean