Subtraktion und Skalarmultiplikation hinzugefügt und getestet

vector.py

@@ -25,6 +25,14 @@ class Vector(object):
     def plus(self,v):
     	  new_coordinates = [x+y for x,y in zip(self.coordinates, v.coordinates)]
     	  return Vector(new_coordinates)
+    
+    def minus(self,v):
+    	  new_coordinates = [x-y for x,y in zip(self.coordinates, v.coordinates)]
+    	  return Vector(new_coordinates)
+    	  
+    def times_scalar(self, c):
+    	new_coordinates = [c*x for x in self.coordinates]
+    	return Vector(new_coordinates)
 
 # Tests
 
@@ -37,4 +45,8 @@ vektor_3 = Vector([-1,2,3])
 print vektor_1 == vektor_2
 print vektor_2 == vektor_3 
 
-print vektor_1.plus(vektor_2)
+print vektor_1.plus(vektor_2)
+
+print vektor_2.minus(vektor_3)
+
+print vektor_3.times_scalar(3)