[R] elements in a matrix to a vector

[Mike Jones]

my apologies to everyone taking the time to answer this question.  i
didn't explain myself very well.  

i have the indices of the elements of the matrix and the matrix won't
necessarily have zeros everywhere else.  is there a way to use the
indices to strip the elements i need?

thanks again...mj

-----Original Message-----
From: Dave Roberts [mailto:droberts at montana.edu] 
Sent: Wednesday, November 09, 2005 12:28 PM
To: Mike Jones
Cc: r-help at stat.math.ethz.ch
Subject: Re: [R] elements in a matrix to a vector


Mike,

    It's not clear whaty way you are doing it now, but this works

 > x <- matrix(c(0,2,0,0,0,4,3,0,0),nrow=3)
 > x
      [,1] [,2] [,3]
[1,]    0    0    3
[2,]    2    0    0
[3,]    0    4    0
 > y <- as.vector(t(x))
 > z <- y[y!=0]
 > z
[1] 3 2 4


Dave



Mike Jones wrote:
> hi all,
> 
> i'm trying to get elements in a matrix into a vector.  i need a 
> "streamlined" way to do it as the way i'm doing it is not very 
> serviceable.  an example is a 3x3 matrix like
> 
> 0 0 3
> 2 0 0
> 0 4 0
> 
> to a vector like
> 
> 3 2 4
> 
> thanks...mj
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list 
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! 
> http://www.R-project.org/posting-guide.html
> 
> 


-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
David W. Roberts                                     office 406-994-4548
Professor and Head                                      FAX 406-994-3190
Department of Ecology                         email droberts at montana.edu
Montana State University
Bozeman, MT 59717-3460