Minor improvements in class Vector

diff --git a/doc/reference.rst b/doc/reference.rst
index de5300d..4e71658 100644 (file)
--- a/doc/reference.rst
+++ b/doc/reference.rst
@@ -677,7 +677,7 @@ Geometric Objects
     .. method:: cross(vector)
 
         Compute the cross product of two 3D vectors.
-        If either one of the vectors is not tridimensional, a :exc:`ValueError` exception is raised.
+        If either one of the vectors is not three-dimensional, a :exc:`ValueError` exception is raised.
 
     .. method:: dot(vector)
 

diff --git a/linpy/geometry.py b/linpy/geometry.py
index a0a7b7c..43344e4 100644 (file)
--- a/linpy/geometry.py
+++ b/linpy/geometry.py
@@ -231,7 +231,7 @@ class Vector(Coordinates):
     def __new__(cls, initial, terminal=None):
         """
         Create a vector from a dictionary or a sequence that maps the symbols to
-        their coordinates, or as the difference between two points.
+        their coordinates, or as the displacement between two points.
         """
         if not isinstance(initial, Point):
             initial = Point(initial)
@@ -283,10 +283,10 @@ class Vector(Coordinates):
         """
         Multiplies a Vector by a scalar value.
         """
-        if not isinstance(other, numbers.Real):
-            return NotImplemented
-        coordinates = self._map(lambda coordinate: other * coordinate)
-        return Vector(coordinates)
+        if isinstance(other, numbers.Real):
+            coordinates = self._map(lambda coordinate: other * coordinate)
+            return Vector(coordinates)
+        return NotImplemented
 
     __rmul__ = __mul__
 
@@ -295,17 +295,18 @@ class Vector(Coordinates):
         Divide the vector by the specified scalar and returns the result as a
         vector.
         """
-        if not isinstance(other, numbers.Real):
-            return NotImplemented
-        coordinates = self._map(lambda coordinate: coordinate / other)
-        return Vector(coordinates)
+        if isinstance(other, numbers.Real):
+            coordinates = self._map(lambda coordinate: coordinate / other)
+            return Vector(coordinates)
+        return NotImplemented
 
     def __eq__(self, other):
         """
         Test whether two vectors are equal.
         """
-        return isinstance(other, Vector) and \
-            self._coordinates == other._coordinates
+        if isinstance(other, Vector):
+            return self._coordinates == other._coordinates
+        return NotImplemented
 
     def angle(self, other):
         """
@@ -321,7 +322,7 @@ class Vector(Coordinates):
     def cross(self, other):
         """
         Compute the cross product of two 3D vectors. If either one of the
-        vectors is not tridimensional, a ValueError exception is raised.
+        vectors is not three-dimensional, a ValueError exception is raised.
         """
         if not isinstance(other, Vector):
             raise TypeError('other must be a Vector instance')
@@ -348,7 +349,7 @@ class Vector(Coordinates):
         return result
 
     def __hash__(self):
-        return hash(tuple(self.coordinates()))
+        return super().__hash__()
 
     def norm(self):
         """