updated documentation for rotations.misorientation

hexrd/rotations.py

@@ -145,10 +145,23 @@ def invertQuat(q):
 
 def misorientation(q1, q2, *args):
     """
-    sym is a tuple (crystal_symmetry, *sample_symmetry)
-    generally coded.
-
-    !!! may split up special cases for no symmetry or crystal/sample only...
+    PARAMETERS
+    ----------
+    q1: array(4, 1)
+        a single quaternion
+    q2: array(4, n)
+        array of quaternions
+    *args: tuple
+        there can be only one extra argument, which is 1- or 2-tuple with
+        symmetries (quaternion arrays); for crystal symmetry only,
+        use a 1-tuple; with both crystal and sample symmetry use a 2-tuyple
+
+    RETURNS
+    -------
+    angle: array(n)
+        the misorientation angle between `q1` and each quaternion in `q2`
+    mis: array(4, n)
+        the quaternion of the smallest misorientation angle
     """
     if not isinstance(q1, ndarray) or not isinstance(q2, ndarray):
         raise RuntimeError("quaternion args are not of type `numpy ndarray'")

tests/test_rotations.py

@@ -0,0 +1,26 @@
+"""Test rotations module"""
+import numpy as np
+import pytest
+
+from hexrd.material import symmetry
+from hexrd import rotations
+
+
+def test_misorientations():
+    """Use Laue groups to test for zero misorientation"""
+    #
+    # This tests that all the 11 Laue groups have zero misorientation with
+    # their own members.
+    #
+    laue_groups = [
+        "ci", "c2h", "d2h", "c4h", "d4h", "c3i",
+        "d3d", "c6h", "d6h", "th", "oh"
+    ]
+    for lg in laue_groups:
+        print("group: ", lg)
+        qsym = symmetry.quatOfLaueGroup(lg)
+        q1 = qsym[:, -1:]
+        ang, mis = rotations.misorientation(q1, qsym, (qsym,))
+        assert np.allclose(ang, 0.0)
+        assert np.allclose(mis[0, :], 1.)
+        assert np.allclose(mis[1:, :], 0.)