SciPy

scipy.stats.ansari

scipy.stats.ansari(x, y)[source]

Perform the Ansari-Bradley test for equal scale parameters

The Ansari-Bradley test is a non-parametric test for the equality of the scale parameter of the distributions from which two samples were drawn.

Parameters :

x, y : array_like

arrays of sample data

Returns :

AB : float

The Ansari-Bradley test statistic

p-value : float

The p-value of the hypothesis test

See also

fligner
A non-parametric test for the equality of k variances
mood
A non-parametric test for the equality of two scale parameters

Notes

The p-value given is exact when the sample sizes are both less than 55 and there are no ties, otherwise a normal approximation for the p-value is used.

References

[R217]Sprent, Peter and N.C. Smeeton. Applied nonparametric statistical methods. 3rd ed. Chapman and Hall/CRC. 2001. Section 5.8.2.