matrix_factorization.py 文件源码

def update_weight_param(self, mu0, r, u, c, v):
        # Returns the weight parameters in an 1-D array in the row major order
        # and also the mean estimate of matrix factorization as a by-product.

        mu = self.compute_model_mean(self.y_coo.row, self.y_coo.col, mu0, r, u, c, v)

        if math.isinf(self.prior_param['obs_df']):
            phi = self.prior_param['weight']
        else:
            prior_shape = self.prior_param['obs_df'] / 2
            prior_rate = self.prior_param['obs_df'] / 2 / self.prior_param['weight']
            sq_error = (self.y_coo.data - mu) ** 2
            post_shape = prior_shape + 1 / 2
            post_rate = prior_rate + sq_error / 2
            phi = np.random.gamma(post_shape, 1 / post_rate)

        return phi, mu