docs: def compute_sens(self, elem_file, elec_file, configs):
          """
          Compute the sensitivities for the given input data.
          A CRMod instance is called to create the sensitivity files.
          """
          CRMod_config = CRMod.config()
          # activate 2D mode and set sink nr
          if self.options.sink is not None:
              print('2D mode with sink {0}'.format(self.options.sink))
              CRMod_config['2D'] = 0
              CRMod_config['fictitious_sink'] = 'T'
              CRMod_config['sink_node'] = self.options.sink
  
          CRMod_config['write_sens'] = 'T'
          CRMod_instance = CRMod.CRMod(CRMod_config)
          CRMod_instance.elemfile = elem_file
          CRMod_instance.elecfile = elec_file
          CRMod_instance.configdata = configs
  
          resistivity = 100
          # get number of elements
          fid = open(elem_file, 'r')
          fid.readline()
          elements = int(fid.readline().strip().split()[1])
          fid.close()
  
          # create rho.dat file
          rhodata = '{0}\n'.format(elements)
          for i in range(0, elements):
              rhodata += '{0}   0\n'.format(resistivity)
          CRMod_instance.rhodata = rhodata
  
          CRMod_instance.run_in_tempdir()
          volt_file = CRMod_instance.volt_file
          sens_files = CRMod_instance.sens_files
          return sens_files, volt_file, CRMod_instance.temp_dir