code: def addPointVectors(self, vectors, name):
          
          poly = self.polydata(False)
          if len(vectors) != poly.GetNumberOfPoints():
              colors.printc('~times addPointVectors Error: Number of vectors != nr. of points',
                            len(vectors), poly.GetNumberOfPoints(), c=1)
              exit()
          arr = vtk.vtkDoubleArray()
          arr.SetNumberOfComponents(3)
          arr.SetName(name)
          for v in vectors:
              arr.InsertNextTuple(v)
          poly.GetPointData().AddArray(arr)
          poly.GetPointData().SetActiveVectors(name)
          return self
docs: Add a point vector field to the actor's polydata assigning it a name.