code: def zpk2ss(z, p, k):
      """Zero-pole-gain representation to state-space representation
  
      Parameters
      ----------
      z, p : sequence
          Zeros and poles.
      k : float
          System gain.
  
      Returns
      -------
      A, B, C, D : ndarray
          State space representation of the system, in controller canonical
          form.
  
      """
      return tf2ss(*zpk2tf(z, p, k))
  
file_path: catboost/contrib/python/scipy/py2/scipy/signal/lti_conversion.py
imports: from __future__ import division, print_function, absolute_import
  import numpy
  import numpy
  from numpy import r_, eye, atleast_2d, poly, dot, asarray, product, zeros, array, outer
  from scipy import linalg
  from .filter_design import tf2zpk, zpk2tf, normalize
label_desc: Use image node_id 9 for calling a global function with example usage: zpk2ss(z, p, k) and returns: tf2ss