skbio.diversity.alpha.
chao1
(counts, bias_corrected=True)[source]¶Calculate chao1 richness estimator.
State: Experimental as of 0.4.0.
Uses the biascorrected version unless bias_corrected is False
and
there are both singletons and doubletons.
Parameters:  counts : 1D array_like, int
bias_corrected : bool, optional


Returns:  double

See also
Notes
The uncorrected version is based on Equation 6 in [R21]:
where \(F_1\) and \(F_2\) are the count of singletons and doubletons, respectively.
The biascorrected version is defined as
References
[R21]  (1, 2) Chao, A. 1984. Nonparametric estimation of the number of classes in a population. Scandinavian Journal of Statistics 11, 265270. 