docstr: This functions provides the centre of mass of the segmented element
  
  :return:
docstr_tok: ["This","functions","provides","the","centre","of","mass","of","the","segmented","element",":","return",":"]
code: def com_seg(self):
      """
      This functions provides the centre of mass of the segmented element
  
      :return:
      """
      if self.flag_empty:
          return -1
      return ndimage.center_of_mass(self.seg)
  
imports: from __future__ import absolute_import, print_function
  import numpy
  from scipy import ndimage
  from niftynet.utilities.util_common import MorphologyOps, CacheFunctionOutput
label_desc: Use image node_id 32 for calling the PairwiseMeasures obj's underlying member method code with example usage: obj.com_seg() and returns: ndimage, unknown