# skbio.math.diversity.alpha.robbins¶

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

Calculate Robbins’ estimator for the probability of unobserved outcomes.

Robbins’ estimator is defined as

$\frac{F_1}{n+1}$

where $$F_1$$ is the number of singleton OTUs.

Parameters: counts : 1-D array_like, int Vector of counts. double Robbins’ estimate.

Notes

Robbins’ estimator is defined in [R53]. The estimate computed here is for $$n-1$$ counts, i.e. the x-axis is off by 1.

References

 [R53] (1, 2) Robbins, H. E (1968). Ann. of Stats. Vol 36, pp. 256-257.