def from_euler(cls, euler):
"""Creates a rotation from an array of Euler angles.
Parameters
----------
euler : array-like
Euler angles in the Bunge convention.
"""
# Bunge convention
euler = np.array(euler)
n = euler.shape[:-1]
alpha, beta, gamma = euler[..., 0], euler[..., 1], euler[..., 2]
alpha -= np.pi / 2
gamma -= 3 * np.pi / 2
zero = np.zeros(n)
qalpha = Quaternion(
np.stack((np.cos(alpha / 2), zero, zero, np.sin(alpha / 2)),
axis=-1))
qbeta = Quaternion(
np.stack((np.cos(beta / 2), zero, np.sin(beta / 2), zero),
axis=-1))
qgamma = Quaternion(
np.stack((np.cos(gamma / 2), zero, zero, np.sin(gamma / 2)),
axis=-1))
data = qalpha * qbeta * qgamma
rot = cls(data.data)
rot.improper = zero
return rot
def __mul__(self, other):
if isinstance(other, Rotation):
q = Quaternion(self) * Quaternion(other)
r = other.__class__(q)
i = np.logical_xor(self.improper, other.improper)
r.improper = i
return r
if isinstance(other, Quaternion):
q = Quaternion(self) * other
return q
if isinstance(other, Vector3d):
v = Quaternion(self) * other
improper = (self.improper * np.ones(other.shape)).astype(bool)
v[improper] = -v[improper]
return v
try:
other = np.atleast_1d(other).astype(int)
except ValueError:
pass
if isinstance(other, np.ndarray):
assert np.all(
abs(other) == 1), "Rotations can only be multiplied by 1 or -1"
r = Rotation(self.data)
r.improper = np.logical_xor(self.improper, other == -1)
return r
return NotImplemented
def __gt__(self, other):
c = Quaternion(self).dot_outer(Quaternion(other)).data
inside = np.logical_or(np.all(np.greater_equal(c, 0), axis=0),
np.all(np.less_equal(c, 0), axis=0))
return inside
def quaternion(request):
return Quaternion(request.param)
def test_init(input_length):
with pytest.raises(DimensionError):
Quaternion(tuple(range(input_length)))
def something(request):
return Quaternion(request.param)
def identity():
return Quaternion((1, 0, 0, 0))
def test_multiply_vector(quaternion, vector, expected):
q = Quaternion(quaternion)
v = Vector3d(vector)
v_new = q * v
assert np.allclose(v_new.data, expected)
import numpy as np
import pytest
from texpy.base import DimensionError
from texpy.quaternion import Quaternion
from texpy.vector import Vector3d
values = [(0.707, 0., 0., 0.707), (0.5, -0.5, -0.5, 0.5), (0., 0., 0., 1.),
(1., 1., 1., 1.), (
(0.5, -0.5, -0.5, 0.5),
(0., 0., 0., 1.),
),
Quaternion([[
(0., 0., 0., 1.),
(0.707, 0., 0., 0.707),
], [
(1., 1., 1., 1.),
(0.707, 0., 0., 0.707),
]]),
np.array((4, 3, 2, 1))]
@pytest.fixture(params=values)
def quaternion(request):
return Quaternion(request.param)
@pytest.fixture
def identity():
return Quaternion((1, 0, 0, 0))