[R] To transform an adjacency matrix

[Pascal Oettli]

Hello,

One approach is:

m <- structure(c(0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0,
0, 0, 1, 0, 0, 0, 0), .Dim = c(5L, 5L))
out <- which(m==1, arr.ind=TRUE)
out[order(out[,1]),]

Regards,
Pascal

On 20 November 2013 19:28, Arnaud Michel <michel.arnaud at cirad.fr> wrote:
> Hi
> I have the following problem
> I would like to build, from a matrix filled with 0 and with 1, a matrix
> or a data.frame which contains, in every line, the number of the line
> and the number of the column of the matrix for which the value is equal
> to 1.
> Exemple :
>
> dput(m)
> structure(c(0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1,
> 0, 0, 0, 1, 0, 0, 0, 0), .Dim = c(5L, 5L))
>
> Result
>
> 1 5
> 2 3
> 2 4
> 4 1
> 4 3
>
> Thank you for your help
>
> --
> Michel ARNAUD
> Chargé de mission auprès du DRH
> DGDRD-Drh - TA 174/04
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> fax : 04.67.61.57.87
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>
>
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-- 
Pascal Oettli
Project Scientist
JAMSTEC
Yokohama, Japan