polishing

python/damask/_rotation.py

@@ -502,7 +502,7 @@ class Rotation:
                                     np.ones( qu.shape[:-1]+(1,))*np.pi,
                                     np.zeros(qu.shape[:-1]+(1,))]),
                           eu)                                                                       # TODO: Where can be nested
-        # reduce Euler angles to definition range, i.e a lower limit of 0.0
+        # reduce Euler angles to definition range
         eu[np.abs(eu)<1.e-6] = 0.0
         eu = np.where(eu<0, (eu+2.0*np.pi)%np.array([2.0*np.pi,np.pi,2.0*np.pi]),eu)
         return eu
@@ -559,10 +559,10 @@ class Rotation:
     def qu2ho(qu):
         """Quaternion to homochoric vector."""
         if len(qu.shape) == 1:
-            if np.isclose(qu[0],1.0):
+            omega = 2.0 * np.arccos(np.clip(qu[0],-1.0,1.0))
+            if np.abs(omega) < 1.0e-12:
                 ho = np.zeros(3)
             else:
-                omega = 2.0 * np.arccos(np.clip(qu[0],-1.0,1.0))
                 ho = np.array([qu[1], qu[2], qu[3]])
                 f  = 0.75 * ( omega - np.sin(omega) )
                 ho = ho/np.linalg.norm(ho) * f**(1./3.)

python/tests/test_Rotation.py

@@ -167,7 +167,7 @@ class TestRotation:
         conversion(qu.reshape(qu.shape[0]//2,-1,4))
         co = conversion(qu)
         for q,c in zip(qu,co):
-            #print(q,c)
+            print(q,c)
             assert np.allclose(conversion(q),c)
 
     @pytest.mark.parametrize('conversion',[Rotation.om2qu,