code: def variation(a, axis=0):
      """
      Computes the coefficient of variation, the ratio of the biased standard
      deviation to the mean.
  
      Parameters
      ----------
      a : array_like
          Input array.
      axis : int or None, optional
          Axis along which to calculate the coefficient of variation. Default
          is 0. If None, compute over the whole array `a`.
  
      Returns
      -------
      variation : ndarray
          The calculated variation along the requested axis.
  
      Notes
      -----
      For more details about `variation`, see `stats.variation`.
  
      """
      a, axis = _chk_asarray(a, axis)
      return a.std(axis) / a.mean(axis)
  
imports: from __future__ import division, print_function, absolute_import
  import numpy
  from numpy import ndarray
  import numpy.ma
  from numpy.ma import masked, nomask
  from scipy._lib.six import iteritems
  import itertools
  import warnings
  from collections import namedtuple
  from .None import distributions
  import scipy.special
  from ._stats_mstats_common import _find_repeats, linregress, theilslopes, siegelslopes
label_desc: Use image node_id 43 for calling a global function with example usage: variation(a, axis) and returns: unknown