raref2: Estimates the species richness for a given number of sampled...

In rich: Computes and Compares Species Richnesses

Description

raref2 computes an estimation of the species richness by thinning the data matrix so that the overall corresponding density is comprised in a fixed interval.

Usage

raref2(matrix, dens, tolerance, nrandom=99)

Arguments

matrix	matrix is a typical species-sample matrix. Rows correspond to samples whereas columns stand for species.
dens	A number corresponding to the density for which a species richness estimation is required.dens must be comprised within the range of the observed density.
tolerance	A number used to calculate the range of acceptable values for the density of simulated communities. Let D be largest density (com1 or com2). The acceptable interval is D \pm tolerance \times D.
nrandom	nrandom is the number of a randomizations used in the bootstrap estimation. Values of nrandom <10 or NULL are set to 99.

Value

raref2 returns a list with two components.

mean.boot	The mean value of the bootstrap estimates of the species richness.
sd.boot	The standard deviation of the bootstrap estimates.

Author(s)

Jean-Pierre Rossi [e-mail]

See Also

raref, rich

Examples

## Not run: 
data(ef)
raref2(matrix=ef,dens=1100,tolerance=0.01,nrandom=50)

## End(Not run)

rich documentation built on May 2, 2019, 5:25 p.m.