# skbio.diversity.alpha.simpson¶

skbio.diversity.alpha.simpson(counts)[source]

Calculate Simpson’s index.

State: Experimental as of 0.4.0.

Simpson’s index is defined as 1 - dominance:

$1 - \sum{p_i^2}$

where $$p_i$$ is the proportion of the community represented by OTU $$i$$.

Parameters: counts : 1-D array_like, int Vector of counts. double Simpson’s index.

Notes

The implementation here is 1 - dominance as described in [R9596]. Other references (such as [R9696]) define Simpson’s index as 1 / dominance.

References

 [R9596] (1, 2) http://folk.uio.no/ohammer/past/diversity.html