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
Statistical Computing Facility
Department of Statistics
UC Berkeley
spector at stat.berkeley.edu
On Wed, 1 Dec 2010, Barroso, Judit wrote:
> 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 like to continue the model writing some condition when the value of
the matrix in not null, but I don't know what function or loop I have to use
to find the values > than 0 for the next step.
>
> pop <- matrix(0,7,7)# Population matrix when t==0
> pop[sample(1:length(pop),1)] <-1 #Population matrix when t==1
>
> Thanks a lot,
> Judit
>
> [[alternative HTML version deleted]]
>
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