def test_rotate_and_move_dipole(self, quadrant_points):
vx = sphere.potential_homogeneous_dipole(
1., 1., [0.5, 0, 0], [1, 0, 0], quadrant_points)
M = np.array([[0, 1, 0], [1, 0, 0], [0, 0, 1]])
vy = sphere.potential_homogeneous_dipole(
1., 1., [0, 0.5, 0], [0, 1, 0], M.dot(quadrant_points.T).T)
M = np.array([[0, 0, 1], [0, 1, 0], [1, 0, 0]])
vz = sphere.potential_homogeneous_dipole(
1., 1., [0, 0, 0.5], [0, 0, 1], M.dot(quadrant_points.T).T)
np.testing.assert_allclose(vx, vy)
np.testing.assert_allclose(vx, vz)
def test_compare_homogeneous(self, quadrant_points):
p = sphere.fibonacci_sphere(11, 2)
v1 = sphere.potential_dipole_3layers(
[0.8, 0.9, 2], 1., 1., [0, 0, 0.5], [1, 1, 1], p, 500)
v2 = sphere.potential_homogeneous_dipole(
2., 1., [0, 0, 0.5], [1, 1, 1], p)
assert np.allclose(v1, v2)
def test_tangential_dipole(self, quadrant_points):
''' Tests the relationship between a 3-sphere and single sphere model, Ari et. al
1998 '''
b_bar = 0.5
b_tilde = 0.316
m_bar = 1.
m_tilde = 1./1.531
V_3layers = sphere.potential_dipole_3layers([.87, .92, 1.], 1., .0125,
[b_bar, 0, 0], [0, m_bar, 0],
quadrant_points)
V_homo = sphere.potential_homogeneous_dipole(1., 1.,
[b_tilde, 0, 0], [0, m_tilde, 0],
quadrant_points)
assert np.allclose(V_3layers, V_homo, rtol=5e-2)
def test_reciprocity():
cond = [1, 1, 1]
radii = [0.7, 0.85, 1]
electrodes = np.array(((1, 0, 0), (-1, 0, 0)), dtype=float)
dipole_pos = np.array(
((0.5, 0, 0), (0.5 + 1e-10, 0., 0), (0.5, 1e-10, 0), (0.5, 0, 1e-10),
(0.5 - 1e-10, 0., 0), (0.5, -1e-10, 0), (0.5, 0, -1e-10)),
dtype=float)
dipole_moment = np.array((1, 1, 1), dtype=float)
pot = sphere.potential_3layers_surface_electrodes(radii, cond,
electrodes[0, :],
electrodes[1, :],
dipole_pos)
E_field = (pot[1:4] - pot[4:7]) / 2e-13
dipole_pot = sphere.potential_homogeneous_dipole(1., 1., dipole_pos[0],
dipole_moment, electrodes)
np.testing.assert_allclose(dipole_pot[0] - dipole_pot[1],
-E_field.dot(dipole_moment),
rtol=1e-4)
def test_move_dipole_xyz(self, quadrant_points):
v = sphere.potential_homogeneous_dipole(
1., 1., [0.5, 0.5, 0.5], [1, 0, 0], quadrant_points)
v2 = sphere.potential_homogeneous_dipole(
1., 1., [-0.5, -0.5, -0.5], [-1, 0, 0], -quadrant_points)
np.testing.assert_almost_equal(v, v2)
def test_tilt_dipole_x(self, quadrant_points):
v = sphere.potential_homogeneous_dipole(
1., 1., [0, 0, 0], [1, 0, 0], quadrant_points)
np.testing.assert_almost_equal(v[quadrant_points[:, 0] > 0],
-v[quadrant_points[:, 0] < 0])
def test_symmetry_z_axis(self, quadrant_points):
v = sphere.potential_homogeneous_dipole(
1., 1., [0, 0, 0], [0, 0, 1], quadrant_points)
np.testing.assert_almost_equal(v[quadrant_points[:, 2] > 0],
-v[quadrant_points[:, 2] < 0])
def test_dipole_source_at_center(self):
points = np.array([[0, 0.7071, 0.7071]])
v = sphere.potential_homogeneous_dipole(
1., 1., [0, 0, 0], [0, 0, 1], points)
v_simple = 3 / (4 * np.pi * 1e-6) * (1 / np.sqrt(2))
assert np.abs((v[0] - v_simple) / v_simple) < 1e-3
