when subsetting a matrix results in a single row, it is converted to a
vector, not a matrix.
how do I avoid this?
1. __GOOD__
> edges <- get.edges(g,E(g))
> edges
[,1] [,2]
[1,] 0 2
[2,] 0 3
[3,] 0 4
[4,] 0 5
[5,] 1 1
[6,] 0 4
[7,] 0 6
[8,] 0 7
[9,] 0 8
[10,] 0 9
[11,] 0 5
[12,] 0 10
[13,] 0 11
[14,] 0 12
[15,] 0 11
[16,] 0 13
[17,] 0 14
[18,] 0 15
[19,] 0 16
[20,] 1 17
[21,] 1 11
[22,] 0 11
> loops <- edges[,1] == edges[,2]
> loopless <- edges[!loops,]
> loopless
loopless
[,1] [,2]
[1,] 0 2
[2,] 0 3
[3,] 0 4
[4,] 0 5
[5,] 0 4
[6,] 0 6
[7,] 0 7
[8,] 0 8
[9,] 0 9
[10,] 0 5
[11,] 0 10
[12,] 0 11
[13,] 0 12
[14,] 0 11
[15,] 0 13
[16,] 0 14
[17,] 0 15
[18,] 0 16
[19,] 1 17
[20,] 1 11
[21,] 0 11
> unique(loopless[,1])
[1] 0 1
2. __BAD__
> edges
[,1] [,2]
[1,] 0 1
[2,] 0 0
Browse[1]> edges[!loops,]
[1] 0 1
why is it a vector, not a matrix?
Browse[1]> loopless
[1] 0 1
Browse[1]> loopless[,1]
Error during wrapup: incorrect number of dimensions
--
Sam Steingold (http://sds.podval.org/) on Ubuntu 11.10 (oneiric) X 11.0.11004000
http://www.childpsy.net/ http://iris.org.il http://truepeace.org
http://thereligionofpeace.com http://camera.org http://www.memritv.org
Lottery is a tax on statistics ignorants. MS is a tax on computer-idiots.
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
