code: def _load_mtdata(gzfile):
      
      path = os.path.join(os.path.dirname(__file__), 'tests', 'data', gzfile)
      return np.loadtxt(gzip.open(path))
docs: Simple helper function that finds the test data in the directory tree
      and loads it using :func:`gzip.open` and :func:`numpy.loadtxt`.
  
      :param gzfile: Filename
      :type gzfile: str
      :returns: data
      :rtype: numpy.ndarray