skbio.diversity.alpha.enspie

skbio.diversity.alpha.enspie(counts, finite=False)

Calculate ENS_pie alpha diversity measure.

The effective number of species (ENS) derived from Hurlbert’s probability of interspecific encounter (PIE) ([1], [2]) is defined as:

\[ENS_{pie} = \frac{1}{\sum_{i=1}^S{p_i^2}}\]

where \(S\) is the number of taxa and \(p_i\) is the proportion of the sample represented by taxon \(i\).

Therefore, \(ENS_{pie}\) is equivalent to the inverse Simpson index (1 / D).

Parameters:

counts1-D array_like, int

Vector of counts.

finitebool, optional

If True, correct for finite sampling.

Returns:

float

ENS_pie alpha diversity measure.

See also

inv_simpson

dominance

Notes

enspie is an alias for inv_simpson.

References

[1]

Chase, J. M., & Knight, T. M. (2013). Scale-dependent effect sizes of ecological drivers on biodiversity: why standardised sampling is not enough. Ecology letters, 16, 17-26.

[2]

Hurlbert, S. H. (1971). The nonconcept of species diversity: a critique and alternative parameters. Ecology, 52(4), 577-586.