factorizes the matrix Cui using an implicit alternating least squares
    algorithm. Note: this method is deprecated, consider moving to the
    AlternatingLeastSquares class instead

def alternating_least_squares(Ciu, factors, **kwargs):
    """ factorizes the matrix Cui using an implicit alternating least squares
    algorithm. Note: this method is deprecated, consider moving to the
    AlternatingLeastSquares class instead

    """
    log.warning("This method is deprecated. Please use the AlternatingLeastSquares"
                " class instead")

    model = AlternatingLeastSquares(factors=factors, **kwargs)
    model.fit(Ciu)
    return model.item_factors, model.user_factors