code: def _ar_transparams(params):
      """
      Transforms params to induce stationarity/invertability.
  
      Parameters
      ----------
      params : array_like
          The AR coefficients
  
      Reference
      ---------
      Jones(1980)
      """
      newparams = np.tanh(params / 2)
      tmp = np.tanh(params / 2)
      for j in range(1, len(params)):
          a = newparams[j]
          for kiter in range(j):
              tmp[kiter] -= a * newparams[j - kiter - 1]
          newparams[:j] = tmp[:j]
      return newparams
  
imports: from __future__ import annotations
  from statsmodels.compat.python import Literal, lrange
  import warnings
  import numpy
  import pandas
  from pandas import DataFrame
  from pandas.tseries import offsets
  from pandas.tseries.frequencies import to_offset
  from statsmodels.tools.data import _is_recarray, _is_using_pandas
  from statsmodels.tools.sm_exceptions import ValueWarning
  from statsmodels.tools.typing import NDArray
  from statsmodels.tools.validation import array_like, bool_like, int_like, string_like
label_desc: Use image node_id 16 for calling a global function with example usage: _ar_transparams(params) and returns: newparams