Formula as follow: where D m is McIntosh diversity index,N is the total number of individuals in the plant population, N i is the number of individuals of the i th species. R function as follow: #A R function for calculating the mcIntosh diversity index mcIntosh-function(x,MARGIN = 1){ x - drop(as.matrix(x)) if (length(dim(x)) 1) { total - apply(x, MARGIN, sum) Dm-(total-(rowSums(x^2))^0.5)/(total-total^0.5) } else { Dm - (sum(x)-(sum(x^2))^0.5)/(sum(x)-sum(x)^0.5)} return(Dm) } Example: library(vegan) data(BCI) mcIntosh(BCI) mcIntosh.txt
标签: McIntosh
