scipy.stats.variation

scipy.stats.variation(a, axis=0, nan_policy='propagate')

Compute the coefficient of variation, the ratio of the biased standard deviation to the mean.

Parameters

aarray_like

Input array.

axisint 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. ‘propagate’ returns nan, ‘raise’ throws an error, ‘omit’ performs the calculations ignoring nan values. Default is ‘propagate’.

Returns

variationndarray

The calculated variation along the requested axis.

References

1

Zwillinger, D. and Kokoska, S. (2000). CRC Standard Probability and Statistics Tables and Formulae. Chapman & Hall: New York. 2000.

Examples

>>> from scipy.stats import variation
>>> variation([1, 2, 3, 4, 5])
0.47140452079103173