text: #!/usr/bin/env python3
  # -*- coding: utf-8 -*-
  """
  Created on Mon Dec 10 14:47:47 2018
  
  @author: kyungdoehan
  """
  
  import flopy
  import os 
  class paths:
      def __init__(self):
          self.fdirmpexe = os.getcwd() + "/exe/"
          self.fnmpexe = 'mp6'
          
  class particle_tracking:
      def __init__(self, fdirmpexe, )