species richness lower bound

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Description

This function implements the Chao1 diversity index.

Usage

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chao1(data, print=TRUE, answers=FALSE)

Arguments

data

The sample frequency count table for the population of interest. See breakaway for details.

print

Logical: whether the results should be printed to screen.

answers

Logical: whether the function should return an argument.

Value

name

The “name” of the model.

est

The estimate of total (observed plus unobserved) diversity.

seest

The standard error in the diversity estimate.

ci

An asymmetric 95% confidence interval for diversity.

Note

This estimator is based on the assumption of equal species detection probabilities, that is, every group in the population is equally likely to be observed. This assumption never applies, thus this should never be used for species richness estimation. However, it provides a reliable lower bound for species richness, and has historical significance. breakaway, breakaway_nof1 and chao_bunge provide viable alternatives for species richness estimation and are included in this package.

Author(s)

Amy Willis

References

Chao, A. (1984). Nonparametric estimation of the number of classes in a population. Scandinavian Journal of Statistics, 4.

See Also

breakaway; apples; wlrm_untransformed; chao1_bc; chao_bunge

Examples

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