small changes suggested by Franz

python/damask/orientation.py

@@ -83,7 +83,7 @@ class Rotation:
             ])
         elif other.shape == (3,3,):                                                                 # rotate a single (3x3)-matrix
            return np.dot(self.asMatrix(),np.dot(other,self.asMatrix().T))
-        elif other.shape == (3,3,3,3):
+        elif other.shape == (3,3,3,3,):
           raise NotImplementedError
         else:
           return NotImplemented

python/damask/quaternion.py

@@ -78,10 +78,8 @@ class Quaternion:
         return NotImplemented
         
     def __neg__(self):                                                                      
-      """Unary positive operator"""  
-      self.q *= -1.0
-      self.p *= -1.0                                                                     
-      return self
+      """Unary negative operator"""  
+      return self * -1.0
       
       
     def __mul__(self, other):
@@ -208,8 +206,7 @@ class Quaternion:
 
     def homomorph(self):
       """Homomorphs in-place"""
-      self.q = -self.q
-      self.p = -self.p
+      self *= -1.0
       return self
       
     def homomorphed(self):