sgcrf.py 文件源码

def check_pd(A, lower=True):
    """
    Checks if A is PD.
    If so returns True and Cholesky decomposition,
    otherwise returns False and None
    """
    try:
        return True, np.tril(cho_factor(A, lower=lower)[0])
    except LinAlgError as err:
        if 'not positive definite' in str(err):
            return False, None