Compute dissimilarity estimates between two samples based on Expected Species Shared (ESS)-measures, using abundance data for the species contained in each samples

ess(x, m = 1, index = "CNESSa")

Arguments

x: a community data matrix (sample x species); sample name is the row name of the matrix
m: the sample size parameter that represents the number of individuals randomly drawn from each sample, which by default is set to m=1, but can be changed according to the users' requirements. Rows with a total sample size <m will be excluded automatically from the analysis.
index: the distance measure used in the calculation, as one of the four options "CNESSa", "CNESS","NESS" and "ESS", with the default set as "CNESSa"

Value

a pair-wised matrix

References

zou2020rarestR

Examples

data(share, package = 'rarestR')
ess(share)
#>           1         2
#> 2 0.7970962          
#> 3 0.6359703 0.7642330
ess(share, m = 100)
#>           1         2
#> 2 0.8566624          
#> 3 0.7308390 0.8229221
ess(share, m = 100, index = "ESS")
#>          1        2
#> 2 13.01735         
#> 3 22.65674 13.23924