SciPy

scipy.stats.mstats.skew

scipy.stats.mstats.skew(a, axis=0, bias=True)[source]

Computes the skewness of a data set.

For normally distributed data, the skewness should be about 0. A skewness value > 0 means that there is more weight in the left tail of the distribution. The function skewtest can be used to determine if the skewness value is close enough to 0, statistically speaking.

Parameters :

a : ndarray

data

axis : int or None

axis along which skewness is calculated

bias : bool

If False, then the calculations are corrected for statistical bias.

Returns :

skewness : ndarray

The skewness of values along an axis, returning 0 where all values are equal.

References

[CRCProbStat2000] Section 2.2.24.1

[CRCProbStat2000](1, 2) Zwillinger, D. and Kokoska, S. (2000). CRC Standard Probability and Statistics Tables and Formulae. Chapman & Hall: New York. 2000.