randomizedEigensolver.py 文件源码

def BorthogonalityTest(B, U):
    """
    Test the frobenious norm of  U^TBU - I_k
    """
    BU = np.zeros(U.shape)
    Bu = Vector()
    u = Vector()
    B.init_vector(Bu,0)
    B.init_vector(u,1)

    nvec  = U.shape[1]
    for i in range(0,nvec):
        u.set_local(U[:,i])
        B.mult(u,Bu)
        BU[:,i] = Bu.get_local()

    UtBU = np.dot(U.T, BU)
    err = UtBU - np.eye(nvec, dtype=UtBU.dtype)
    print("|| UtBU - I ||_F = ", np.linalg.norm(err, 'fro') )