rareNMtests (version 1.2)

chao1: Computes the Chao 1 species richness estimator

Description

Computes the Chao 1 richness estimator, its estimated variance, and the corresponding 95

Usage

chao1(x)

Arguments

x

Vector of species abundances.

Value

A data frame with five columns including the observed number of species (Sobs), the estimated number of species with the Chao 1 estimator (S.chao1), the estimated variance (var), and the upper and lower 95

Details

Different equations are used to compute the classic Chao1 richness estimator, its estimated variance, and the corresponding 95

References

Chao, A. (1987). Estimating the population size for capture-recapture data with unequal catchability. Biometrics 43, 783-791.

See Also

specpool

Examples

# NOT RUN {
   abund <- c(19, 12, 7, 3, 3, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1)
   print(chao1(abund))
# }