skbio.math.diversity.alpha.simpson

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

Calculate Simpson’s index.

Simpson’s index is defined as 1 - dominance.

Parameters:

counts : 1-D array_like, int

Vector of counts.

Returns:

double

Simpson’s index.

See also

dominance

Notes

The implementation here is 1 - dominance as described in [R55]. Other references (such as [R56]) define Simpson’s index as 1 / dominance.

References

[R55](1, 2) http://folk.uio.no/ohammer/past/diversity.html
[R56](1, 2) http://www.pisces-conservation.com/sdrhelp/index.html