Exposed vector negative to python

src/Base/VectorPy.xml

@@ -32,6 +32,13 @@
 				</UserDocu>
 			</Documentation>
 		</Methode>
+		<Methode Name="negative" Const="true">
+			<Documentation>
+				<UserDocu>negative()
+					      returns the negative (opposite) of this vector
+				</UserDocu>
+			</Documentation>
+		</Methode>
 		<Methode Name="scale">
 			<Documentation>
 				<UserDocu>scale(Float,Float,Float)

src/Base/VectorPyImp.cpp

@@ -215,6 +215,16 @@ PyObject*  VectorPy::sub(PyObject *args)
     return new VectorPy(v);
 }
 
+PyObject*  VectorPy::negative(PyObject *args)
+{
+    if (!PyArg_ParseTuple(args, ""))
+        return 0;
+        
+    VectorPy::PointerType this_ptr = reinterpret_cast<VectorPy::PointerType>(_pcTwinPointer);
+    Base::Vector3d v = -(*this_ptr);
+    return new VectorPy(v);
+}
+
 PyObject* VectorPy::richCompare(PyObject *v, PyObject *w, int op)
 {
     if (PyObject_TypeCheck(v, &(VectorPy::Type)) &&