def test_rotate(self):
# ensure that selection isn't centered at 0, 0, 0
self.u.atoms.translate((1, 1, 1))
self.coords += 1
# check identify does nothing
R = np.eye(3)
self.u.atoms.rotate(R)
assert_array_almost_equal(self.u.atoms.positions, self.coords)
# check default rotation center is at 0, 0, 0. Changing this center
# will break an unpredictable amount of old code.
ag = self.u.atoms[:2]
ag.positions = np.array([[1, 0, 0], [-1, 0, 0]])
ag.rotate(transformations.rotation_matrix(1, [0, 0, 1])[:3, :3])
assert_array_almost_equal(ag.positions[0], [np.cos(1), np.sin(1), 0])
# check general rotation cases
vec = np.array([[1, 0, 0], [-1, 0, 0]])
axis = np.array([0, 0, 1])
for angle in np.linspace(0, np.pi):
R = transformations.rotation_matrix(angle, axis)
ag.positions = vec.copy()
res_ag = ag.rotate(R[:3, :3])
assert_equal(ag, res_ag)
assert_array_almost_equal(
ag.positions[0],
[np.cos(angle), np.sin(angle), 0])
ag.positions = vec.copy()
ag.rotate(R[:3, :3], vec[0])
assert_array_almost_equal(ag.positions[0], vec[0])
assert_array_almost_equal(
ag.positions[1],
[-2 * np.cos(angle) + 1, -2 * np.sin(angle), 0])
def test_rotation_from_matrix():
angle = (random.random() - 0.5) * (2*np.pi)
direc = np.random.random(3) - 0.5
point = np.random.random(3) - 0.5
R0 = t.rotation_matrix(angle, direc, point)
angle, direc, point = t.rotation_from_matrix(R0)
R1 = t.rotation_matrix(angle, direc, point)
assert_equal(t.is_same_transform(R0, R1), True)
def test_rotation_from_matrix():
angle = (random.random() - 0.5) * (2 * np.pi)
direc = np.random.random(3) - 0.5
point = np.random.random(3) - 0.5
R0 = t.rotation_matrix(angle, direc, point)
angle, direc, point = t.rotation_from_matrix(R0)
R1 = t.rotation_matrix(angle, direc, point)
assert_equal(t.is_same_transform(R0, R1), True)
def test_rotation_from_matrix():
angle = 0.2 * 2 * np.pi # arbitrary values
direc = np.array([0.2, 0.2, 0.2])
point = np.array([0.4, 0.4, 0.4])
R0 = t.rotation_matrix(angle, direc, point)
angle, direc, point = t.rotation_from_matrix(R0)
R1 = t.rotation_matrix(angle, direc, point)
assert_equal(t.is_same_transform(R0, R1), True)
def test_rotation_from_matrix():
angle = 0.2 * 2 * np.pi # arbitrary values
direc = np.array([0.2, 0.2, 0.2])
point = np.array([0.4, 0.4, 0.4])
R0 = t.rotation_matrix(angle, direc, point)
angle, direc, point = t.rotation_from_matrix(R0)
R1 = t.rotation_matrix(angle, direc, point)
assert_equal(t.is_same_transform(R0, R1), True)
def rotation(xyz, idx, max_angle):
angle = np.random.uniform(0, max_angle)
vec = xyz[idx + 1] - xyz[idx - 1]
vec /= norm(vec)
x = xyz[idx] - xyz[idx - 1]
mat = transformations.rotation_matrix(angle, vec)[:3, :3]
xyz[idx] = np.dot(mat, x) + xyz[idx - 1]
return xyz
def test_rotation_matrix():
# test if the rotation_matrix function is working properly
# simple angle and unit vector on origin
angle = 180
vector = [0, 0, 1]
pos = [0, 0, 0]
ref_matrix = np.asarray([[-1, 0, 0], [0, -1, 0], [0, 0, 1]], np.float64)
matrix = rotation_matrix(np.deg2rad(angle), vector, pos)[:3, :3]
assert_array_almost_equal(matrix, ref_matrix, decimal=6)
# another angle in a custom axis
angle = 60
vector = [1, 2, 3]
pos = [1, 2, 3]
ref_matrix = np.asarray([[0.53571429, -0.6229365, 0.57005291],
[0.76579365, 0.64285714, -0.01716931],
[-0.35576719, 0.44574074, 0.82142857]],
np.float64)
matrix = rotation_matrix(np.deg2rad(angle), vector, pos)[:3, :3]
assert_array_almost_equal(matrix, ref_matrix, decimal=6)
def test_rotation_matrix():
# test if the rotation_matrix function is working properly
# simple angle and unit vector on origin
angle = 180
vector = [0, 0, 1]
pos = [0, 0, 0]
ref_matrix = np.asarray([[-1, 0, 0],
[0, -1, 0],
[0, 0, 1]], np.float64)
matrix = rotation_matrix(np.deg2rad(angle), vector, pos)[:3, :3]
assert_array_almost_equal(matrix, ref_matrix, decimal=6)
# another angle in a custom axis
angle = 60
vector = [1, 2, 3]
pos = [1, 2, 3]
ref_matrix = np.asarray([[ 0.53571429, -0.6229365 , 0.57005291],
[ 0.76579365, 0.64285714, -0.01716931],
[-0.35576719, 0.44574074, 0.82142857]], np.float64)
matrix = rotation_matrix(np.deg2rad(angle), vector, pos)[:3, :3]
assert_array_almost_equal(matrix, ref_matrix, decimal=6)
def test_fit_rot_trans_no_options(fit_universe):
test_u = fit_universe[0]
ref_u = fit_universe[1]
ref_com = ref_u.atoms.center(None)
ref_u.trajectory.ts.positions -= ref_com
R = rotation_matrix(np.pi / 3, [1, 0, 0])[:3, :3]
ref_u.trajectory.ts.positions = np.dot(ref_u.trajectory.ts.positions, R)
ref_u.trajectory.ts.positions += ref_com
fit_rot_trans(test_u, ref_u)(test_u.trajectory.ts)
assert_array_almost_equal(test_u.trajectory.ts.positions,
ref_u.trajectory.ts.positions,
decimal=3)
def test_rotateby_vector(rotate_universes, vector):
# what happens when we use a custom point for the axis of rotation?
ref_u = rotate_universes[0]
trans_u = rotate_universes[1]
trans = trans_u.trajectory.ts
ref = ref_u.trajectory.ts
point = [0, 0, 0]
angle = 90
vec = vector.reshape(3, )
matrix = rotation_matrix(np.deg2rad(angle), vec, point)
ref_u.atoms.transform(matrix)
transformed = rotateby(angle, vector, point=point)(trans)
assert_array_almost_equal(transformed.positions, ref.positions, decimal=6)
def test_rotateby_vector(rotate_universes, vector):
# what happens when we use a custom point for the axis of rotation?
ref_u = rotate_universes[0]
trans_u = rotate_universes[1]
trans = trans_u.trajectory.ts
ref = ref_u.trajectory.ts
point = [0, 0, 0]
angle = 90
vec = vector.reshape(3, )
matrix = rotation_matrix(np.deg2rad(angle), vec, point)
ref_u.atoms.transform(matrix)
transformed = rotateby(angle, vector, point=point)(trans)
assert_array_almost_equal(transformed.positions, ref.positions, decimal=6)
def test_transform_translation_and_rotation(self):
angle = np.pi / 4
axis = [0, 0, 1]
disp = np.ones(3)
T = transformations.rotation_matrix(angle, axis)
T[:3, 3] = disp
ag = self.u.atoms[:2]
ag.positions = [[1, 0, 0], [-1, 0, 0]]
ag.transform(T)
assert_array_almost_equal(
ag.positions[0],
[np.cos(angle) + 1, np.sin(angle) + 1, 1])
def test_rotateby_atomgroup_cog_nopbc(rotate_universes):
# what happens when we rotate arround the center of geometry of a residue
# without pbc?
ref_u = rotate_universes[0]
trans_u = rotate_universes[1]
trans = trans_u.trajectory.ts
ref = ref_u.trajectory.ts
center_pos = [6,7,8]
vector = [1,0,0]
angle = 90
matrix = rotation_matrix(np.deg2rad(angle), vector, center_pos)
ref_u.atoms.transform(matrix)
selection = trans_u.residues[0].atoms
transformed = rotateby(angle, vector, ag=selection, weights=None)(trans)
assert_array_almost_equal(transformed.positions, ref.positions, decimal=6)
def test_rotateby_atomgroup_com_pbc(rotate_universes):
# what happens when we rotate arround the center of mass of a residue
# with pbc?
ref_u = rotate_universes[0]
trans_u = rotate_universes[1]
trans = trans_u.trajectory.ts
ref = ref_u.trajectory.ts
vector = [1,0,0]
angle = 90
selection = trans_u.residues[0].atoms
center_pos = selection.center_of_mass(pbc=True)
matrix = rotation_matrix(np.deg2rad(angle), vector, center_pos)
ref_u.atoms.transform(matrix)
transformed = rotateby(angle, vector, ag=selection, weights='mass', wrap=True)(trans)
assert_array_almost_equal(transformed.positions, ref.positions, decimal=6)
def test_rotateby_atomgroup_cog_nopbc(rotate_universes):
# what happens when we rotate arround the center of geometry of a residue
# without pbc?
ref_u = rotate_universes[0]
trans_u = rotate_universes[1]
trans = trans_u.trajectory.ts
ref = ref_u.trajectory.ts
center_pos = [6, 7, 8]
vector = [1, 0, 0]
angle = 90
matrix = rotation_matrix(np.deg2rad(angle), vector, center_pos)
ref_u.atoms.transform(matrix)
selection = trans_u.residues[0].atoms
transformed = rotateby(angle, vector, ag=selection, weights=None)(trans)
assert_array_almost_equal(transformed.positions, ref.positions, decimal=6)
def rotation(angle, random_state=None):
"""random rotation with given angle about a random axis
Parameters
----------
angle : float
angle in radian
Returns
-------
M : ndarray (3, 3)
rotation matrix
"""
random_state = check_random_state(random_state)
axis = random_state.normal(size=3)
r = transformations.rotation_matrix(angle, axis)
return r[:3, :3]
def test_transform_rotation_only(self):
R = np.eye(3)
self.u.atoms.rotate(R)
assert_array_almost_equal(self.u.atoms.positions, self.coords)
vec = np.array([[1, 0, 0], [-1, 0, 0]])
axis = np.array([0, 0, 1])
ag = self.u.atoms[:2]
ag.positions = vec
for angle in np.linspace(0, np.pi):
R = transformations.rotation_matrix(angle, axis)
ag.positions = vec.copy()
ag.transform(R)
assert_array_almost_equal(
ag.positions[0],
[np.cos(angle), np.sin(angle), 0])
def test_rotateby_atomgroup_com_pbc(rotate_universes):
# what happens when we rotate arround the center of mass of a residue
# with pbc?
ref_u = rotate_universes[0]
trans_u = rotate_universes[1]
trans = trans_u.trajectory.ts
ref = ref_u.trajectory.ts
vector = [1, 0, 0]
angle = 90
selection = trans_u.residues[0].atoms
center_pos = selection.center_of_mass(pbc=True)
matrix = rotation_matrix(np.deg2rad(angle), vector, center_pos)
ref_u.atoms.transform(matrix)
transformed = rotateby(angle,
vector,
ag=selection,
weights='mass',
wrap=True)(trans)
assert_array_almost_equal(transformed.positions, ref.positions, decimal=6)
def test_fit_rot_trans_plane(fit_universe, plane):
# the reference is rotated in the x axis so removing the translations and rotations
# in the yz plane should return the same as the fitting without specifying a plane
test_u = fit_universe[0]
ref_u = fit_universe[1]
ref_com = ref_u.atoms.center(None)
mobile_com = test_u.atoms.center(None)
axes = {'yz': 0, 'xz': 1, 'xy': 2}
idx = axes[plane]
rotaxis = np.asarray([0, 0, 0])
rotaxis[idx] = 1
ref_u.trajectory.ts.positions -= ref_com
R = rotation_matrix(np.pi / 3, rotaxis)[:3, :3]
ref_u.trajectory.ts.positions = np.dot(ref_u.trajectory.ts.positions, R)
ref_com[idx] = mobile_com[idx]
ref_u.trajectory.ts.positions += ref_com
fit_rot_trans(test_u, ref_u, plane=plane)(test_u.trajectory.ts)
assert_array_almost_equal(test_u.trajectory.ts.positions[:, idx],
ref_u.trajectory.ts.positions[:, idx],
decimal=3)
def right_angle_mat():
return transformations.rotation_matrix(np.radians(90), [1, -1, 1])[:3, :3]
def test_quaternion_matrix_1(self):
M = self.f([0.99810947, 0.06146124, 0, 0])
assert_allclose(M, t.rotation_matrix(0.123, (1, 0, 0)), atol=_ATOL)
def test_quaternion_from_matrix_3(self):
R = t.rotation_matrix(0.123, (1, 2, 3))
q = self.f(R, True)
assert_allclose(q, [0.9981095, 0.0164262, 0.0328524, 0.0492786], atol=_ATOL)
def test_quaternion_matrix_1(self):
M = self.f([0.99810947, 0.06146124, 0, 0])
assert_allclose(M, t.rotation_matrix(0.123, (1, 0, 0)), atol=_ATOL)
def test_quaternion_from_matrix_3(self):
R = t.rotation_matrix(0.123, (1, 2, 3))
q = self.f(R, True)
assert_allclose(q, [0.9981095, 0.0164262, 0.0328524, 0.0492786],
atol=_ATOL)
