def test_resample_coil_rotate():
coil_dipole_pos = np.array(
np.meshgrid(np.linspace(-1, 1, 11), np.linspace(-.5, .5, 5),
np.linspace(-.2, .2, 3))).reshape(3, -1).T
coil_dipole_weights = np.zeros_like(coil_dipole_pos)
coil_dipole_weights[:, 1] = np.linalg.norm(coil_dipole_pos, axis=1)
coil_dir = []
for angle in np.linspace(np.pi / 2, np.pi, 7):
coil_dir.append([-np.sin(angle), np.cos(angle), 0])
coil_dir = np.array(coil_dir)
resampled_positions, resampled_weights = ADMlib.resamplecoil(
coil_dipole_pos.T, coil_dipole_weights.T, [17, 17, 2], len(coil_dir),
coil_dir.T)
resampled_positions = resampled_positions
# Define some arbitrary function to be integrated
def func(pos):
return np.array([
pos[0]**2 + pos[1],
pos[1]**3 + pos[2],
pos[0]**3 + pos[2],
])
z = np.array([0, 0, 1])
for i, cd in enumerate(coil_dir):
rotation_matrix = np.array([np.cross(cd, z), cd, z]).T
positions_rotated = rotation_matrix.dot(coil_dipole_pos.T)
weights_rotated = rotation_matrix.dot(coil_dipole_weights.T)
assert np.isclose(
np.sum(weights_rotated * func(positions_rotated)),
np.sum(resampled_weights[:, :, i] * func(resampled_positions)))
def test_resample_coil_no_rotation():
coil_dipole_pos = np.array(
np.meshgrid(np.linspace(-1, 1, 11), np.linspace(-1, 1, 11),
np.linspace(-.2, .2, 3))).reshape(3, -1).T
coil_dipole_weights = np.ones_like(coil_dipole_pos)
resampled_positions, resampled_weights = ADMlib.resamplecoil(
coil_dipole_pos.T, coil_dipole_weights.T, [17, 17, 2], 1,
np.array([[0, 1, 0]]).T)
resampled_positions = resampled_positions.T
resampled_weights = resampled_weights[..., 0].T
# Define some arbitrary function to be integrated
def func(pos):
return np.array([
pos[:, 0]**2 + pos[:, 1],
pos[:, 1]**3 + pos[:, 2],
pos[:, 0]**3 + pos[:, 2],
]).T
assert np.isclose(np.sum(coil_dipole_weights * func(coil_dipole_pos)),
np.sum(resampled_weights * func(resampled_positions)))