class_docstr: MultiSubjectParcellation class are used to represent parcels
  that can have different spatial different contours
  in a given group of subject
  It consists of
  self.domain: the specification of a domain
  self.template_labels the specification of a template parcellation
  self.individual_labels the specification of individual parcellations
  
  fixme:should inherit from mroi.MultiROI
class_docstr_tok: ["MultiSubjectParcellation","class","are","used","to","represent","parcels","that","can","have","different","spatial","different","contours","in","a","given","group","of","subject","It","consists","of","self.domain",":","the","specification","of","a","domain","self.template_labels","the","specification","of","a","template","parcellation","self.individual_labels","the","specification","of","individual","parcellations","fixme",":","should","inherit","from","mroi.MultiROI"]
docstr: Returns the counting of labels per voxel per subject
  
  Returns
  -------
  population: array of shape (self.nb_parcel, self.nb_subj)
docstr_tok: ["Returns","the","counting","of","labels","per","voxel","per","subject","Returns","--","--","--","-","population",":","array","of","shape","(","self.nb_parcel",",","self.nb_subj",")"]
code: def population(self):
      """Returns the counting of labels per voxel per subject
  
      Returns
      -------
      population: array of shape (self.nb_parcel, self.nb_subj)
      """
      population = np.zeros((self.nb_parcel, self.nb_subj)).astype(
          np.int_
      )
      for ns in range(self.nb_subj):
          for k in range(self.nb_parcel):
              population[k, ns] = np.sum(
                  self.individual_labels[:, ns] == k
              )
      return population
  
file_path: nipy/nipy/labs/spatial_models/parcellation.py
imports: from warnings import warn
  import numpy
label_desc: Use image node_id 6 for calling the MultiSubjectParcellation obj's underlying member method code with example usage: obj.population() and returns: population