def test_tetragonal_direction2(self):
ZrO2 = Lattice.tetragonal(0.364, 0.527)
d = HklDirection(1, 1, 1, ZrO2)
target = np.array([1., 1., 1.448])
target /= np.linalg.norm(target)
self.assertAlmostEqual(d.direction()[0], target[0], 4)
self.assertAlmostEqual(d.direction()[1], target[1], 4)
self.assertAlmostEqual(d.direction()[2], target[2], 4)
def test_tetragonal_direction(self):
bct = Lattice.body_centered_tetragonal(0.28, 0.40)
d111 = HklDirection(1, 1, 1, bct)
d110 = HklDirection(1, 1, 0, bct)
self.assertAlmostEqual(d111.direction()[0], 0.49746834, 5)
self.assertAlmostEqual(d111.direction()[1], 0.49746834, 5)
self.assertAlmostEqual(d111.direction()[2], 0.71066905, 5)
self.assertAlmostEqual(d110.direction()[0], 0.707106781, 5)
self.assertAlmostEqual(d110.direction()[1], 0.707106781, 5)
self.assertAlmostEqual(d110.direction()[2], 0.0, 5)
def test_angle_zone(self):
"""Verify the angle between X and a particular zone axis expressed
in (X, Y, Z), given a crystal orientation."""
# euler angles in degrees
phi1 = 89.4
phi = 92.0
phi2 = 86.8
orientation = Orientation.from_euler([phi1, phi, phi2])
gt = orientation.orientation_matrix().transpose()
# zone axis
uvw = HklDirection(1, 0, 5, self.ni)
ZA = gt.dot(uvw.direction())
if ZA[0] < 0:
ZA *= -1 # make sur the ZA vector is going forward
psi0 = np.arccos(np.dot(ZA, np.array([1., 0., 0.])))
self.assertAlmostEqual(psi0 * 180 / np.pi, 9.2922, 3)
def zone_axis_list(angle,
orientation,
lattice,
max_miller=5,
Xu=np.array([1., 0., 0.]),
verbose=False):
"""
This function allows to get easily the Miller indices of zone axis present in a pattern.
:param float list angle: the angle max or the zone axis angle range admissible around the detector center.
:param orientation: The orientation of the crystal lattice.
:param lattice: The corresponding crystal lattice, instance of Lattice.
:param int max_miller: Maximal value allowed of Miller indices direction.
:param array Xu: The unit vector of the incident X-ray beam (default along the X-axis).
:param bool verbose: activate verbose mode (default False).
:return: A list of HklDirection instance of all zone axis in the angle range.
"""
ZA_list = []
if len(angle) == 1:
angle_max = angle[0] * np.pi / 180.
angle_min = 0.
if len(angle) == 2:
angle_max = max(angle) * np.pi / 180.
angle_min = min(angle) * np.pi / 180.
print("Get the indices of directions between [%d, %d] degrees" %
(min(angle), max(angle)))
indices = range(-max_miller, max_miller + 1)
for h in indices:
for k in indices:
for l in indices:
if h == k == l == 0: # skip (0, 0, 0)
continue
uvw = HklDirection(h, k, l, lattice)
# compute the direction in the lab frame
ZA = np.dot(orientation.orientation_matrix().transpose(),
uvw.direction())
psi = np.arccos(np.dot(ZA, Xu))
if angle_min < psi < angle_max:
if verbose == True:
print(
'found zone axis [%d%d%d] at %.1f deg from incident beam'
% (h, k, l, (psi * 180 / pi)))
ZA_list.append(
uvw
) #zones axis list which are inferior with max angle
ZA_list = HklObject.skip_higher_order(ZA_list)
return ZA_list