introduction_to_recommender.../P3. k-nearest neighbours.ipynb
Robert Kwiecinski 0f00fb0454 2nd meeting
2021-04-16 22:41:06 +02:00

35 KiB

Self made simplified I-KNN

import helpers
import pandas as pd
import numpy as np
import scipy.sparse as sparse
from collections import defaultdict
from itertools import chain
import random

train_read = pd.read_csv("./Datasets/ml-100k/train.csv", sep="\t", header=None)
test_read = pd.read_csv("./Datasets/ml-100k/test.csv", sep="\t", header=None)
(
    train_ui,
    test_ui,
    user_code_id,
    user_id_code,
    item_code_id,
    item_id_code,
) = helpers.data_to_csr(train_read, test_read)
class IKNN:
    def fit(self, train_ui):
        self.train_ui = train_ui

        train_iu = train_ui.transpose()
        norms = np.linalg.norm(
            train_iu.A, axis=1
        )  # here we compute length of each item ratings vector
        norms = np.vectorize(lambda x: max(x, 1))(
            norms[:, None]
        )  # to avoid dividing by zero

        normalized_train_iu = sparse.csr_matrix(train_iu / norms)

        self.similarity_matrix_ii = (
            normalized_train_iu * normalized_train_iu.transpose()
        )

        self.estimations = np.array(
            train_ui
            * self.similarity_matrix_ii
            / ((train_ui > 0) * self.similarity_matrix_ii)
        )

    def recommend(self, user_code_id, item_code_id, topK=10):

        top_k = defaultdict(list)
        for nb_user, user in enumerate(self.estimations):

            user_rated = self.train_ui.indices[
                self.train_ui.indptr[nb_user] : self.train_ui.indptr[nb_user + 1]
            ]
            for item, score in enumerate(user):
                if item not in user_rated and not np.isnan(score):
                    top_k[user_code_id[nb_user]].append((item_code_id[item], score))
        result = []
        # Let's choose k best items in the format: (user, item1, score1, item2, score2, ...)
        for uid, item_scores in top_k.items():
            item_scores.sort(key=lambda x: x[1], reverse=True)
            result.append([uid] + list(chain(*item_scores[:topK])))
        return result

    def estimate(self, user_code_id, item_code_id, test_ui):
        result = []
        for user, item in zip(*test_ui.nonzero()):
            result.append(
                [
                    user_code_id[user],
                    item_code_id[item],
                    self.estimations[user, item]
                    if not np.isnan(self.estimations[user, item])
                    else 1,
                ]
            )
        return result
# toy example
toy_train_read = pd.read_csv(
    "./Datasets/toy-example/train.csv",
    sep="\t",
    header=None,
    names=["user", "item", "rating", "timestamp"],
)
toy_test_read = pd.read_csv(
    "./Datasets/toy-example/test.csv",
    sep="\t",
    header=None,
    names=["user", "item", "rating", "timestamp"],
)

(
    toy_train_ui,
    toy_test_ui,
    toy_user_code_id,
    toy_user_id_code,
    toy_item_code_id,
    toy_item_id_code,
) = helpers.data_to_csr(toy_train_read, toy_test_read)


model = IKNN()
model.fit(toy_train_ui)

print("toy train ui:")
display(toy_train_ui.A)

print("similarity matrix:")
display(model.similarity_matrix_ii.A)

print("estimations matrix:")
display(model.estimations)

model.recommend(toy_user_code_id, toy_item_code_id)
toy train ui:
array([[3, 4, 0, 0, 5, 0, 0, 4],
       [0, 1, 2, 3, 0, 0, 0, 0],
       [0, 0, 0, 5, 0, 3, 4, 0]])
similarity matrix:
array([[1.        , 0.9701425 , 0.        , 0.        , 1.        ,
        0.        , 0.        , 1.        ],
       [0.9701425 , 1.        , 0.24253563, 0.12478355, 0.9701425 ,
        0.        , 0.        , 0.9701425 ],
       [0.        , 0.24253563, 1.        , 0.51449576, 0.        ,
        0.        , 0.        , 0.        ],
       [0.        , 0.12478355, 0.51449576, 1.        , 0.        ,
        0.85749293, 0.85749293, 0.        ],
       [1.        , 0.9701425 , 0.        , 0.        , 1.        ,
        0.        , 0.        , 1.        ],
       [0.        , 0.        , 0.        , 0.85749293, 0.        ,
        1.        , 1.        , 0.        ],
       [0.        , 0.        , 0.        , 0.85749293, 0.        ,
        1.        , 1.        , 0.        ],
       [1.        , 0.9701425 , 0.        , 0.        , 1.        ,
        0.        , 0.        , 1.        ]])
estimations matrix:
array([[4.        , 4.        , 4.        , 4.        , 4.        ,
               nan,        nan, 4.        ],
       [1.        , 1.35990333, 2.15478388, 2.53390319, 1.        ,
        3.        , 3.        , 1.        ],
       [       nan, 5.        , 5.        , 4.05248907,        nan,
        3.95012863, 3.95012863,        nan]])
[[0, 20, 4.0, 30, 4.0],
 [10, 50, 3.0, 60, 3.0, 0, 1.0, 40, 1.0, 70, 1.0],
 [20, 10, 5.0, 20, 5.0]]
model = IKNN()
model.fit(train_ui)

top_n = pd.DataFrame(model.recommend(user_code_id, item_code_id, topK=10))

top_n.to_csv(
    "Recommendations generated/ml-100k/Self_IKNN_reco.csv", index=False, header=False
)

estimations = pd.DataFrame(model.estimate(user_code_id, item_code_id, test_ui))
estimations.to_csv(
    "Recommendations generated/ml-100k/Self_IKNN_estimations.csv",
    index=False,
    header=False,
)
import evaluation_measures as ev

estimations_df = pd.read_csv(
    "Recommendations generated/ml-100k/Self_IKNN_estimations.csv", header=None
)
reco = np.loadtxt("Recommendations generated/ml-100k/Self_IKNN_reco.csv", delimiter=",")

ev.evaluate(
    test=pd.read_csv("./Datasets/ml-100k/test.csv", sep="\t", header=None),
    estimations_df=estimations_df,
    reco=reco,
    super_reactions=[4, 5],
)
943it [00:00, 9004.71it/s]
RMSE MAE precision recall F_1 F_05 precision_super recall_super NDCG mAP MRR LAUC HR Reco in test Test coverage Shannon Gini
0 1.018363 0.808793 0.000318 0.000108 0.00014 0.000189 0.0 0.0 0.000214 0.000037 0.000368 0.496391 0.003181 0.392153 0.11544 4.174741 0.965327
dir_path = "Recommendations generated/ml-100k/"
super_reactions = [4, 5]
test = pd.read_csv("./Datasets/ml-100k/test.csv", sep="\t", header=None)

ev.evaluate_all(test, dir_path, super_reactions)
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943it [00:00, 12064.07it/s]
Model RMSE MAE precision recall F_1 F_05 precision_super recall_super NDCG mAP MRR LAUC HR Reco in test Test coverage Shannon Gini
0 Self_TopPop 2.508258 2.217909 0.188865 0.116919 0.118732 0.141584 0.130472 0.137473 0.214651 0.111707 0.400939 0.555546 0.765642 1.000000 0.038961 3.159079 0.987317
0 Ready_Baseline 0.949459 0.752487 0.091410 0.037652 0.046030 0.061286 0.079614 0.056463 0.095957 0.043178 0.198193 0.515501 0.437964 1.000000 0.033911 2.836513 0.991139
0 Ready_Random 1.521845 1.225949 0.047190 0.020753 0.024810 0.032269 0.029506 0.023707 0.050075 0.018728 0.121957 0.506893 0.329799 0.986532 0.184704 5.099706 0.907217
0 Self_TopRated 1.030712 0.820904 0.000954 0.000188 0.000298 0.000481 0.000644 0.000223 0.001043 0.000335 0.003348 0.496433 0.009544 0.699046 0.005051 1.945910 0.995669
0 Self_BaselineUI 0.967585 0.762740 0.000954 0.000170 0.000278 0.000463 0.000644 0.000189 0.000752 0.000168 0.001677 0.496424 0.009544 0.600530 0.005051 1.803126 0.996380
0 Self_IKNN 1.018363 0.808793 0.000318 0.000108 0.000140 0.000189 0.000000 0.000000 0.000214 0.000037 0.000368 0.496391 0.003181 0.392153 0.115440 4.174741 0.965327

Ready-made KNNs - Surprise implementation

I-KNN - basic

import helpers
import surprise as sp

sim_options = {
    "name": "cosine",
    "user_based": False,
}  # compute similarities between items
algo = sp.KNNBasic(sim_options=sim_options)

helpers.ready_made(
    algo,
    reco_path="Recommendations generated/ml-100k/Ready_I-KNN_reco.csv",
    estimations_path="Recommendations generated/ml-100k/Ready_I-KNN_estimations.csv",
)
Computing the cosine similarity matrix...
Done computing similarity matrix.
Generating predictions...
Generating top N recommendations...
Generating predictions...

U-KNN - basic

sim_options = {
    "name": "cosine",
    "user_based": True,
}  # compute similarities between users
algo = sp.KNNBasic(sim_options=sim_options)

helpers.ready_made(
    algo,
    reco_path="Recommendations generated/ml-100k/Ready_U-KNN_reco.csv",
    estimations_path="Recommendations generated/ml-100k/Ready_U-KNN_estimations.csv",
)
Computing the cosine similarity matrix...
Done computing similarity matrix.
Generating predictions...
Generating top N recommendations...
Generating predictions...

I-KNN - on top baseline

sim_options = {
    "name": "cosine",
    "user_based": False,
}  # compute similarities between items
algo = sp.KNNBaseline()

helpers.ready_made(
    algo,
    reco_path="Recommendations generated/ml-100k/Ready_I-KNNBaseline_reco.csv",
    estimations_path="Recommendations generated/ml-100k/Ready_I-KNNBaseline_estimations.csv",
)
Estimating biases using als...
Computing the msd similarity matrix...
Done computing similarity matrix.
Generating predictions...
Generating top N recommendations...
Generating predictions...
dir_path = "Recommendations generated/ml-100k/"
super_reactions = [4, 5]
test = pd.read_csv("./Datasets/ml-100k/test.csv", sep="\t", header=None)

ev.evaluate_all(test, dir_path, super_reactions)
943it [00:00, 11286.27it/s]
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943it [00:00, 10779.39it/s]
Model RMSE MAE precision recall F_1 F_05 precision_super recall_super NDCG mAP MRR LAUC HR Reco in test Test coverage Shannon Gini
0 Self_TopPop 2.508258 2.217909 0.188865 0.116919 0.118732 0.141584 0.130472 0.137473 0.214651 0.111707 0.400939 0.555546 0.765642 1.000000 0.038961 3.159079 0.987317
0 Ready_Baseline 0.949459 0.752487 0.091410 0.037652 0.046030 0.061286 0.079614 0.056463 0.095957 0.043178 0.198193 0.515501 0.437964 1.000000 0.033911 2.836513 0.991139
0 Ready_Random 1.521845 1.225949 0.047190 0.020753 0.024810 0.032269 0.029506 0.023707 0.050075 0.018728 0.121957 0.506893 0.329799 0.986532 0.184704 5.099706 0.907217
0 Ready_I-KNN 1.030386 0.813067 0.026087 0.006908 0.010593 0.016046 0.021137 0.009522 0.024214 0.008958 0.048068 0.499885 0.154825 0.402333 0.434343 5.133650 0.877999
0 Ready_I-KNNBaseline 0.935327 0.737424 0.002545 0.000755 0.001105 0.001602 0.002253 0.000930 0.003444 0.001362 0.011760 0.496724 0.021209 0.482821 0.059885 2.232578 0.994487
0 Ready_U-KNN 1.023495 0.807913 0.000742 0.000205 0.000305 0.000449 0.000536 0.000198 0.000845 0.000274 0.002744 0.496441 0.007423 0.602121 0.010823 2.089186 0.995706
0 Self_TopRated 1.030712 0.820904 0.000954 0.000188 0.000298 0.000481 0.000644 0.000223 0.001043 0.000335 0.003348 0.496433 0.009544 0.699046 0.005051 1.945910 0.995669
0 Self_BaselineUI 0.967585 0.762740 0.000954 0.000170 0.000278 0.000463 0.000644 0.000189 0.000752 0.000168 0.001677 0.496424 0.009544 0.600530 0.005051 1.803126 0.996380
0 Self_IKNN 1.018363 0.808793 0.000318 0.000108 0.000140 0.000189 0.000000 0.000000 0.000214 0.000037 0.000368 0.496391 0.003181 0.392153 0.115440 4.174741 0.965327

project task 3: use a version of your choice of Surprise KNNalgorithm

# read the docs and try to find best parameter configuration (let say in terms of RMSE)
# https://surprise.readthedocs.io/en/stable/knn_inspired.html##surprise.prediction_algorithms.knns.KNNBaseline
# the solution here can be similar to examples above
# please save the output in 'Recommendations generated/ml-100k/Self_KNNSurprisetask_reco.csv' and
# 'Recommendations generated/ml-100k/Self_KNNSurprisetask_estimations.csv'