Calculate the Expected Species

es(x, m, method = c("a", "b"), MARGIN = 1)

Arguments

x: a data vector representing number of individuals for each species
m: the sample size parameter that represents the number of individuals randomly drawn from the sample. For ESa, m can not be larger than the sample size
method: the calculation approach of Expected Species used, with two options available as "a" and "b" to calculate ESa and ESb, with the default set as "a"
MARGIN: a vector giving the subscripts which the function will be applied over, see 'apply'.

Value

a value of Expected Species

References

zou2023rarestR

Examples

data(share, package = 'rarestR')
rowSums(share) #The sum size of each sample is 100, 150 and 200
#>   1   2   3 
#> 100 150 200 
es(share, m = 100)
#>        1        2        3 
#> 58.00000 47.77653 53.00568 
es(share, method = "b", m = 100)
#>        1        2        3 
#> 43.51041 40.74378 46.19118 
# When the m is larger than the total sample size, "NA" will be filled:
es(share, m = 150)
#> Warning: m can not be larger than the total sample size
#>        1        2        3 
#>       NA 57.00000 65.24147