Test axis_angles_from_quaternions

pytransform3d/batch_rotations.py

@@ -393,12 +393,12 @@ def axis_angles_from_quaternions(qs):
 
     Parameters
     ----------
-    q : array-like, shape (..., 4)
+    qs : array-like, shape (..., 4)
         Unit quaternion to represent rotation: (w, x, y, z)
 
     Returns
     -------
-    a : array, shape (..., 4)
+    as : array, shape (..., 4)
         Axis of rotation and rotation angle: (x, y, z, angle). The angle is
         constrained to [0, pi) so that the mapping is unique.
     """

pytransform3d/test/test_batch_rotations.py

@@ -1,4 +1,5 @@
 import numpy as np
+
 from pytransform3d import rotations as pr
 from pytransform3d import batch_rotations as pbr
 from numpy.testing import assert_array_almost_equal
@@ -342,6 +343,28 @@ def test_axis_angles_from_matrices_output_variable():
     assert_array_almost_equal(A, A2_compact)
 
 
+def test_axis_angles_from_quaternions():
+    rng = np.random.default_rng(48322)
+    Q = pbr.norm_vectors(rng.standard_normal(size=(20, 4)))
+
+    # 1D
+    pr.assert_quaternion_equal(
+        pbr.axis_angles_from_quaternions(Q[0]),
+        pr.axis_angle_from_quaternion(Q[0])
+    )
+
+    # 2D
+    A = pbr.axis_angles_from_quaternions(Q)
+    for a, q in zip(A, Q):
+        pr.assert_quaternion_equal(a, pr.axis_angle_from_quaternion(q))
+
+    # 3D
+    Q3D = Q.reshape(5, 4, 4)
+    A3D = pbr.axis_angles_from_quaternions(Q3D)
+    for a, q in zip(A3D.reshape(20, 4), Q3D.reshape(20, 4)):
+        pr.assert_quaternion_equal(a, pr.axis_angle_from_quaternion(q))
+
+
 def test_quaternion_slerp_batch_zero_angle():
     rng = np.random.default_rng(228)
     q = pr.random_quaternion(rng)