code: def _hist_bin_sqrt(x, range):
      """
      Square root histogram bin estimator.
  
      Bin width is inversely proportional to the data size. Used by many
      programs for its simplicity.
  
      Parameters
      ----------
      x : array_like
          Input data that is to be histogrammed, trimmed to range. May not
          be empty.
  
      Returns
      -------
      h : An estimate of the optimal bin width for the given data.
      """
      del range  # unused
      return _ptp(x) / np.sqrt(x.size)
  
imports: from __future__ import division, absolute_import, print_function
  import functools
  import operator
  import warnings
  import numpy
  from numpy.compat.py3k import basestring
  from numpy.core import overrides
label_desc: Use image node_id 2 for calling a global function with example usage: _hist_bin_sqrt(x, range) and returns: unknown