code: def vectors(self, array):
          
          if array.ndim != 2:
              raise AssertionError('vector array must be a 2-dimensional array')
          elif array.shape[1] != 3:
              raise RuntimeError('vector array must be 3D')
          elif array.shape[0] != self.n_points:
              raise RuntimeError('Number of vectors be the same as the number of points')
  
          self.point_arrays[DEFAULT_VECTOR_KEY] = array
          self.active_vectors_name = DEFAULT_VECTOR_KEY
docs: Sets the active vector