chao.mincount {preseqR}R Documentation

Estimating the expected number of species represented r or more times

Description

The function estimates the expected number of species represented at least r times in a random sample based on the initial sample using a nonparametric approach by Chao and Shen (2004).

Usage

chao.mincount(n, r=1, k=10)

Arguments

n

A two-column matrix. The first column is the frequency j = 1,2,…; and the second column is n_j, the number of species with each species represented j times in the initial sample. The first column must be sorted in an ascending order.

r

A vector of positive integers. Default is 1.

k

A cutoff for common species. Default is 10.

Value

The constructed estimator for the number of species represneted at least r times in a sample. The input of the estimator is a vector of sampling efforts t, i.e. the relative sample sizes comparing with the initial sample. For example, t = 2 means the sample is twice the size of the initial sample.

Author(s)

Chao Deng

References

Chao, A., & Shen, T. J. (2004). Nonparametric prediction in species sampling. Journal of agricultural, biological, and environmental statistics, 9(3), 253-269.

Examples

## load library
library(preseqR)

## import data
data(FisherButterflyHist)

## construct the estimator for the number of species
## represented at least once, twice or three times in a sample
chao.estimator <- chao.mincount(FisherButterflyHist, r=1:3)

## The number of species represented at least once, twice or three times
## when the sample size is 10 or 20 times of the initial sample
chao.estimator(c(10, 20))

[Package preseqR version 3.1.2 Index]