Repeated fixed number subsampler without replacement

ssN.nr {sub.sample}

Usage

ssN.nr(x, N, num.ss = 10, spp.names = NULL)

Arguments

`x`	a vector of integers, corresponding to counts of species
`N`	Number of individuals to be in subsamples
`num.ss`	Number of subsamples
`spp.names`	a vector of the same length as x. If spp.names = NULL, they will be reported as numbers.

Details

This function randomly selects N individuals from a vector and returns a matrix of subsampled species counts with species in rows and the num.ss subsamples in columns. Note that N*num.ss cannot exceed the total number of individuals in x (sum(x)).

Value

ss.x

a data frame of subsampled counts, with species in rows and subsamples in columns

Author(s)

Chris Walsh: Chris.Walsh@sci.monash.edu.au.

References

Marchant, R. (1989) A subsampler for samples of benthic invertebrates. Bulletin of the Australian Society for Limnology 12, 49-52.

Examples

#10 subsamples of 100 individuals from a sample of invertebrate #samples urban <- read.table("urban.txt", header=TRUE) urban8.100 <- ssN.nr(urban[,8],100, num.ss = 10, spp.names = urban[,1]) urban8.100

Urban Water Ecology