Issue in collaborative filtering code

[schopra6]

Hi , Could you please explain what you are trying to do in this part of the code.

for clust in range (0, num_clusters): 

        alpha = clust_to_items_1[clust, :]
        alpha_beta = beta.multiply(alpha)
        sum_row = alpha_beta.sum(1)[0, 0]
        num_nonzero = alpha_beta.nonzero()[1].__len__() + 0.001
        to_impute = sum_row/num_nonzero
        Z = np.repeat(to_impute, beta.shape[1])
        alpha_z = alpha.multiply(Z)
        idx = beta.nonzero()
        alpha_z[idx] = beta.data

It seems alpha_z was supposed to collection of beta.data instead getting reassigned at every iteration.