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# scipy.stats.wilcoxon

`scipy.stats.``wilcoxon`(x, y=None)

  Calculate the Wilcoxon signed-rank test

  The Wilcoxon signed-rank test tests the null hypothesis that two related samples come from the same distribution. It is a a non-parametric version of the paired T-test.

  Parameters : | x : array_like The first set of measurements y : array_like, optional, default None The second set of measurements. If y is not given, then the x array is considered to be the differences between the two sets of measurements.
  Returns : | z-statistic : float The test statistic under the large-sample approximation that the signed-rank statistic is normally distributed. p-value : float The two-sided p-value for the test

  Notes

  Because the normal approximation is used for the calculations, the samples used should be large. A typical rule is to require that n > 20.

  References

  [R96] | http://en.wikipedia.org/wiki/Wilcoxon_signed-rank_test

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