[R] Transforming a data matrix into a vector

[Charles Ellis]

Brilliant!  Works like a charm.  Thanks both.

Cheers,
Charles

From: Richard M. Heiberger [mailto:rmh at temple.edu] 
Sent: Monday, May 30, 2011 4:36 PM
To: Charles Ellis
Cc: r-help at R-project.org
Subject: Re: [R] Transforming a data matrix into a vector

> tmp <- matrix(c(5,3,1, 1,3,2, 1,2,4), 3, 3)
> tmp
     [,1] [,2] [,3]
[1,]    5    1    1
[2,]    3    3    2
[3,]    1    2    4
> rep(t(tmp), each=3)
 [1] 5 5 5 1 1 1 1 1 1 3 3 3 3 3 3 2 2 2 1 1 1 2 2 2 4 4 4
>
On Mon, May 30, 2011 at 4:22 PM, Charles Ellis <CharlesE at mairesearch.com> wrote:
Hi,

I am trying to transform a data matrix into a vector and have not be able to accomplish want I am looking for.  The setup is as follows. I start with a 3 x 3 matrix:

5 1 3
3 3 2
1 2 4

I would like to transorm it into a 27 x 1 vector of the follwing form

5
5
5
1
1
1
3
3
3
.
.
.
1
1
1
2
2
2
4
4
4

In essense I want to create a vector in which each element of the original matrix is repeated three times, starting with cell [1,1] and ending with cell [3,3].
This is small example of the larger problem I am trying to solve.  The actual data matrix is 352 x 15, and I would like to end up with a 26,400 x 1 vector.  So each element of the data matrix is repeated 5 times.

Any suggestions or hints would be much appreciated.  Thanks!

I am using;
R version 2.12.2 (2011-02-25)
Copyright (C) 2011 The R Foundation for Statistical Computing
ISBN 3-900051-07-0
Platform: i386-pc-mingw32/i386 (32-bit)

Cheers,
Charles

______________________________________________
R-help at 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.