Re: [R] read a matrix to find a value

Judit - Does this example provide any insight? pop <- matrix(0,7,7)# Population matrix when t==0 pop[sample(1:length(pop),1)] <-1 #Population matrix when t==1 which(pop!=0,arr.ind=TRUE) row col [1,] 3 4 - Phil Spector

[R] read a matrix to find a value

Dear all of you, I would like if someone can help me to know how I can read a matrix looking for positions in the matrix that are not null. I have a matrix with most of the "cells" or "positions" null, I am trying to know the invasion power of a plant (number 1 in the matrix when t==1). I would