Week 2 - Collaborative filtering algorithm implementation question

Course Q&A Machine Learning Specialization Unsupervised Learning, Recommenders, Reinforcement
1

Hi, i have a question regarding collaborative algorithm.
Here, feature vector (x) and user vector (w and b params) are learned simultaneously from rating data. All these vectors are initialized with random values.
So… how can we make sure after training x represents feature vector of movie and w and b are for the users.

2

You know this because of the sizes of the X and W matrices. One of them uses the number of users, and the other uses the number of movies.

3

Thanks for the quick reply.
Okay, I think i understood the logic, but what if both are same… say a 100 users and 100 movies

4

That’s just a happy coincidence. It doesn’t change which data is in which rows or columns.

5

Okay, thank you. :+1: