Collaborative Filtering, Matrix Factorization, Recommender Systems, Gradient Descent, Neural Networks.
factor matrices (linear operation) R_hat = U @ V.T # @ means matrix multiplcation, .T means transpose # Calc MSE loss of this reconstruction loss = np.square(R - R_hat).mean() # Calc partial derivative of MSE with respect to U and V U_grad = -2./N * (R - R_hat)@V V_grad = -2./N * (R - R_hat)@U #