skbio.diversity.alpha.simpson

skbio.diversity.alpha.simpson(counts)

Calculate Simpson’s diversity index.

Simpson’s diversity index, a.k.a., Gini-Simpson index, or Gini impurity, is defined as

\[1 - \sum{p_i^2}\]

where \(p_i\) is the proportion of the sample represented by taxon \(i\).

Therefore, Simpson’s diversity index is also denoted as \(1 - D\), in which \(D\) is the Simpson’s dominance index.

Parameters:

counts1-D array_like, int

Vector of counts.

Returns:

double

Simpson’s diversity index.

See also

dominance

Notes

Simpson’s diversity index was originally described in [1].

References

[1]

Simpson, E. H. (1949). Measurement of diversity. Nature, 163(4148), 688-688.