code: def _median_bias(n):
      """
      Returns the bias of the median of a set of periodograms relative to
      the mean.
  
      See arXiv:gr-qc/0509116 Appendix B for details.
  
      Parameters
      ----------
      n : int
          Numbers of periodograms being averaged.
  
      Returns
      -------
      bias : float
          Calculated bias.
      """
      ii_2 = 2 * np.arange(1.0, (n - 1) // 2 + 1)
      return 1 + np.sum(1.0 / (ii_2 + 1) - 1.0 / ii_2)
  
imports: from __future__ import division, print_function, absolute_import
  import numpy
  from scipy import fftpack
  from .None import signaltools
  from .windows import get_window
  from ._spectral import _lombscargle
  from ._arraytools import const_ext, even_ext, odd_ext, zero_ext
  import warnings
  from scipy._lib.six import string_types
label_desc: Use image node_id 14 for calling a global function with example usage: _median_bias(n) and returns: unknown