Score_replace {CFF}

Replacing of Neighbor Users' Ratings on Non-Rated Items By The Active User

Description

The ratings of each user that has more similar to the active user are directly replaced in his unseen items.

Usage

Score_replace(ratings, sim_index, ac)

Arguments

ratings

A rating matrix whose rows are items and columns are users.

sim_index

Descending sorted indexes based on similarity to the active user who is a vector of integers.

ac

The id of an active user as an integer (1\le ac \le length of users).

Details

The unseen items of the active user are filled by the ratings of the similar users, respectively. Each element remains unchanged after one placement.

Value

ratings2

A matrix the size of the original user-item matrix in which the active user's empty elements are filled.

Author(s)

Farimah Houshmand Nanehkaran

Maintainer: Farimah Houshmand Nanehkaran <[e-mail]>

References

Gadekula, S. K., Rao, U. P., Vyas, R. K., Dontula, A. L., & Gaikwad, S. V. (2019). Improved Pearson Similarity for Collaborative Filtering Recommendation System. In 2019 6th International Conference on Computing for Sustainable Global Development (INDIACom), pp. 1047-1054, IEEE.

Examples

ratings <- matrix(c(  2,    5,  NaN,  NaN,  NaN,    4,
                    NaN,  NaN,  NaN,    1,  NaN,    5,
                    NaN,    4,    5,  NaN,    4,  NaN,
                      4,  NaN,  NaN,    5,  NaN,  NaN,
                      5,  NaN,    2,  NaN,  NaN,  NaN,
                    NaN,    1,  NaN,    4,    2,  NaN),nrow=6,byrow=TRUE)

sim <- simple_similarity(ratings, max_score=5, min_score=1, ac=1)

ratings2 <- Score_replace(ratings, sim_index= sim$sim_index, ac=1)