g,pddlZddlmZddlmZmZddlmZedddd d d d Z dS)N)_get_nan)array_namespace xp_copysign)_axis_nan_policy_factoryc|SNxs L/granary/edev/quantum/lib/python3.11/site-packages/scipy/stats/_variation.pyr sac|fSr r r s r rr sr) n_outputsresult_to_tuple propagateF)keepdimscXt|}||}|||d}d}|j|}t |}|jdks||krUt |j}|||||} | j dkr| dn| S| ||} ||krn| ||d} | | dkt||j| |} | j dkr| dn| Stjdd 5| |||} | | z } dddn #1swxYwY| j dkr| dn| S) a Compute the coefficient of variation. The coefficient of variation is the standard deviation divided by the mean. This function is equivalent to:: np.std(x, axis=axis, ddof=ddof) / np.mean(x) The default for ``ddof`` is 0, but many definitions of the coefficient of variation use the square root of the unbiased sample variance for the sample standard deviation, which corresponds to ``ddof=1``. The function does not take the absolute value of the mean of the data, so the return value is negative if the mean is negative. 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`. nan_policy : {'propagate', 'raise', 'omit'}, optional Defines how to handle when input contains ``nan``. The following options are available: * 'propagate': return ``nan`` * 'raise': raise an exception * 'omit': perform the calculation with ``nan`` values omitted The default is 'propagate'. ddof : int, optional Gives the "Delta Degrees Of Freedom" used when computing the standard deviation. The divisor used in the calculation of the standard deviation is ``N - ddof``, where ``N`` is the number of elements. `ddof` must be less than ``N``; if it isn't, the result will be ``nan`` or ``inf``, depending on ``N`` and the values in the array. By default `ddof` is zero for backwards compatibility, but it is recommended to use ``ddof=1`` to ensure that the sample standard deviation is computed as the square root of the unbiased sample variance. Returns ------- variation : ndarray The calculated variation along the requested axis. Notes ----- There are several edge cases that are handled without generating a warning: * If both the mean and the standard deviation are zero, ``nan`` is returned. * If the mean is zero and the standard deviation is nonzero, ``inf`` is returned. * If the input has length zero (either because the array has zero length, or all the input values are ``nan`` and ``nan_policy`` is ``'omit'``), ``nan`` is returned. * If the input contains ``inf``, ``nan`` is returned. References ---------- .. [1] Zwillinger, D. and Kokoska, S. (2000). CRC Standard Probability and Statistics Tables and Formulae. Chapman & Hall: New York. 2000. Examples -------- >>> import numpy as np >>> from scipy.stats import variation >>> variation([1, 2, 3, 4, 5], ddof=1) 0.5270462766947299 Compute the variation along a given dimension of an array that contains a few ``nan`` values: >>> x = np.array([[ 10.0, np.nan, 11.0, 19.0, 23.0, 29.0, 98.0], ... [ 29.0, 30.0, 32.0, 33.0, 35.0, 56.0, 57.0], ... [np.nan, np.nan, 12.0, 13.0, 16.0, 16.0, 17.0]]) >>> variation(x, axis=1, ddof=1, nan_policy='omit') array([1.05109361, 0.31428986, 0.146483 ]) N)r) fill_valuer )axis)r correctionignore)divideinvalid)rasarrayreshapeshapersizelistpopfullndimmeanstdwhererinfnperrstate) ar nan_policyddofrxpnNaNshpresultmean_astd_as r variationr5 sp   B 1 A | JJq%   A 1++Cv{{dQhh17mm  --#[A--vbzz69 WWQTW " "F qyyqt22%!)[BF1C1CV%L%LcRR#[A--vbzz69 Hh 7 7 7  qt55                ))6"::v5s"F  FF)rrr) numpyr)scipy._lib._utilrscipy._lib._array_apirr_axis_nan_policyrr5r rr r:s%%%%%%>>>>>>>>666666K1nnt6Ut6t6t6t6t6t6t6r