text: import numpy as np
  
  from . import geometry
  
  
  def fitting_rmsd(w_fit, C_fit, r_fit, Xs):
      '''Calculate the RMSD of fitting.'''
      return np.sqrt(sum((geometry.point_line_distance(p, C_fit, w_fit) - r_fit) ** 2
                      for p in Xs) / len(Xs)) 
  