class_docstr: Performs connectivity mapping and outputs the result as a NetworkX graph and a Matlab matrix
  
  Example
  -------
  
  >>> import nipype.interfaces.cmtk as cmtk
  >>> conmap = cmtk.CreateMatrix()
  >>> conmap.roi_file = 'fsLUT_aparc+aseg.nii'
  >>> conmap.tract_file = 'fibers.trk'
  >>> conmap.run()                 # doctest: +SKIP
code: def _gen_outfilename(self, ext):
      if ext.endswith("mat") and isdefined(
          self.inputs.out_matrix_mat_file
      ):
          _, name, _ = split_filename(self.inputs.out_matrix_mat_file)
      elif isdefined(self.inputs.out_matrix_file):
          _, name, _ = split_filename(self.inputs.out_matrix_file)
      else:
          _, name, _ = split_filename(self.inputs.tract_file)
      return name + ext
  
imports: import pickle
  import os.path
  import numpy
  import nibabel
  import networkx
  from ...None import logging
  from ...utils.filemanip import split_filename
  from ..base import BaseInterface, BaseInterfaceInputSpec, traits, File, TraitedSpec, Directory, OutputMultiPath, isdefined
label_desc: Use image node_id 3 for calling the CreateMatrix obj's underlying member method code with example usage: obj._gen_outfilename(ext) and returns: unknown