# skbio.diversity.alpha.mcintosh_e¶

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

Calculate McIntosh’s evenness measure E.

State: Experimental as of 0.4.0.

McIntosh evenness measure E is defined as:

$E = \frac{\sqrt{\sum{n_i^2}}}{\sqrt{((N-S+1)^2 + S -1}}$

where $$n_i$$ is the number of individuals in the $$i^{\text{th}}$$ OTU, $$N$$ is the total number of individuals, and $$S$$ is the number of OTUs in the sample.

Parameters

counts (1-D array_like, int) – Vector of counts.

Returns

McIntosh evenness measure E.

Return type

double

Notes

The implementation here is based on the description given in 1, NOT the one in the SDR-IV online manual, which is wrong.

References

1

Heip & Engels (1974) Comparing Species Diversity and Evenness Indices. p 560.