code: def move_point_num(point, to_clust, from_clust, cl_attr_sum, cl_memb_sum):
      
      # Update sum of attributes in cluster.
      for iattr, curattr in enumerate(point):
          cl_attr_sum[to_clust][iattr] += curattr
          cl_attr_sum[from_clust][iattr] -= curattr
      # Update sums of memberships in cluster
      cl_memb_sum[to_clust] += 1
      cl_memb_sum[from_clust] -= 1
      return cl_attr_sum, cl_memb_sum
docs: Move point between clusters, numerical attributes.