docstr: xyz is an (N, 3) array
docstr_tok: ["xyz","is","an","(","N",",","3",")","array"]
code: def apply(self, xyz):
      """
      xyz is an (N, 3) array
      """
      # txyz should be double C-contiguous for the the cython
      # routine _apply_polyaffine
      if self.glob_affine is None:
          txyz = np.array(xyz, copy=True, dtype="double", order="C")
      else:
          txyz = apply_affine(self.glob_affine, xyz)
      _apply_polyaffine(txyz, self.centers, self._affines, self.sigma)
      return txyz
  
file_path: nipy/nipy/algorithms/registration/polyaffine.py
imports: import numpy
  from ._registration import _apply_polyaffine
  from .affine import apply_affine
  from .transform import Transform
label_desc: Use image node_id 4 for calling the PolyAffine obj's underlying member method code with example usage: obj.apply(xyz) and returns: txyz