Exemplo n.º 1
0
def test_euler_instability():
    # Test for numerical errors in mat2euler
    # problems arise for cos(y) near 0
    po2 = pi / 2
    zyx = po2, po2, po2
    M = nea.euler2mat(*zyx)
    # Round trip
    M_back = nea.euler2mat(*nea.mat2euler(M))
    yield assert_true, np.allclose(M, M_back)
    # disturb matrix slightly
    M_e = M - FLOAT_EPS
    # round trip to test - OK
    M_e_back = nea.euler2mat(*nea.mat2euler(M_e))
    yield assert_true, np.allclose(M_e, M_e_back)
    # not so with crude routine
    M_e_back = nea.euler2mat(*crude_mat2euler(M_e))
    yield assert_false, np.allclose(M_e, M_e_back)
Exemplo n.º 2
0
def test_euler_mat():
    M = nea.euler2mat()
    yield assert_array_equal, M, np.eye(3)
    for x, y, z in eg_rots:
        M1 = nea.euler2mat(z, y, x)
        M2 = sympy_euler(z, y, x)
        yield assert_array_almost_equal, M1, M2
        M3 = np.dot(x_only(x), np.dot(y_only(y), z_only(z)))
        yield assert_array_almost_equal, M1, M3
        zp, yp, xp = nea.mat2euler(M1)
        # The parameters may not be the same as input, but they give the
        # same rotation matrix
        M4 = nea.euler2mat(zp, yp, xp)
        yield assert_array_almost_equal, M1, M4