code: def smartirs_normalize(x, norm_scheme, return_norm=False):
      """Normalize a vector using the normalization scheme specified in `norm_scheme`.
  
      Parameters
      ----------
      x : numpy.ndarray
          The tf-idf vector.
      norm_scheme : {'n', 'c'}
          Document length normalization scheme.
      return_norm : bool, optional
          Return the length of `x` as well?
  
      Returns
      -------
      numpy.ndarray
          Normalized array.
      float (only if return_norm is set)
          Norm of `x`.
      """
      if norm_scheme == "n":
          if return_norm:
              _, length = matutils.unitvec(x, return_norm=return_norm)
              return x, length
          else:
              return x
      elif norm_scheme == "c":
          return matutils.unitvec(x, return_norm=return_norm)
  
file_path: gensim/gensim/models/tfidfmodel.py
imports: import logging
  from functools import partial
  import re
  import numpy
  from gensim import interfaces, matutils, utils
  from gensim.utils import deprecated
label_desc: Use image node_id 6 for calling a global function with example usage: smartirs_normalize(x, norm_scheme, return_norm) and returns: x,  length, x, matutils