Converting a Matrix to a Vector

Say I have:
set.seed( 1 )
m <- matrix( runif(5^2), nrow=5, dimnames = list( c("A","B","C","D","E"),
c("O","P","Q","R","S") ) )
m
O          P         Q         R         S
A 0.2655087 0.89838968 0.2059746 0.4976992 0.9347052
B 0.3721239 0.94467527 0.1765568 0.7176185 0.2121425
C 0.5728534 0.66079779 0.6870228 0.9919061 0.6516738
D 0.9082078 0.62911404 0.3841037 0.3800352 0.1255551
E 0.2016819 0.06178627 0.7698414 0.7774452 0.2672207

-------------------------------------------------------------------------------------------

I want to create a vector v from matrix m that looks like this:

A.O 0.2655087
B.O 0.3721239

v <- as.vector( m ) almost gives me what I want, but then I need to take
combinations of colnames( m ) and rownames( m ) to get my labels and hope
they match up in order: if not, manipulate the order.  This approach feels
kludgy...

Is this the right approach or is there a better way?
View this message in context: http://www.nabble.com/Converting-a-Matrix-to-a-Vector-tp22696267p22696267.html
Sent from the R help mailing list archive at Nabble.com.
try this:

set.seed(1)
m <- matrix(runif(5^2), nrow = 5,
     dimnames = list(c("A","B","C","D","E"), c("O","P","Q","R","S")))

v <- c(m)
names(v) <- paste(rownames(m), colnames(m)[col(m)], sep = ".")
# or
# names(v) <- outer(rownames(m), colnames(m), paste, sep = ".")
v

I hope it helps.

Best,
Dimitris
Say I have:

set.seed( 1 )
m <- matrix( runif(5^2), nrow=5, dimnames = list( c("A","B","C","D","E"),
c("O","P","Q","R","S") ) )
m
          O          P         Q         R         S
A 0.2655087 0.89838968 0.2059746 0.4976992 0.9347052
B 0.3721239 0.94467527 0.1765568 0.7176185 0.2121425
C 0.5728534 0.66079779 0.6870228 0.9919061 0.6516738
D 0.9082078 0.62911404 0.3841037 0.3800352 0.1255551
E 0.2016819 0.06178627 0.7698414 0.7774452 0.2672207

-------------------------------------------------------------------------------------------

I want to create a vector v from matrix m that looks like this:

A.O 0.2655087
B.O 0.3721239

v <- as.vector( m ) almost gives me what I want, but then I need to take
combinations of colnames( m ) and rownames( m ) to get my labels and hope
they match up in order: if not, manipulate the order.  This approach feels
kludgy...

Is this the right approach or is there a better way?

Dimitris Rizopoulos
Assistant Professor
Department of Biostatistics
Erasmus University Medical Center

Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands
Tel: +31/(0)10/7043478
Fax: +31/(0)10/7043014
G'day Ken,

On Wed, 25 Mar 2009 00:13:48 -0700 (PDT)

Say I have:

set.seed( 1 )
m <- matrix( runif(5^2), nrow=5, dimnames =
list( c("A","B","C","D","E"), c("O","P","Q","R","S") ) )
m
          O          P         Q         R         S
A 0.2655087 0.89838968 0.2059746 0.4976992 0.9347052
B 0.3721239 0.94467527 0.1765568 0.7176185 0.2121425
C 0.5728534 0.66079779 0.6870228 0.9919061 0.6516738
D 0.9082078 0.62911404 0.3841037 0.3800352 0.1255551
E 0.2016819 0.06178627 0.7698414 0.7774452 0.2672207

-------------------------------------------------------------------------------------------

I want to create a vector v from matrix m that looks like this:

A.O 0.2655087
B.O 0.3721239

v <- as.vector( m ) almost gives me what I want, but then I need to
take combinations of colnames( m ) and rownames( m ) to get my labels
and hope they match up in order: if not, manipulate the order.  This
approach feels kludgy...

Is this the right approach or is there a better way?
R> tt <- reshape(data.frame(m), direction="long", varying=list(1:5), ids=rownames(m), times=colnames(m))
R> ind <- names(tt) %in% c("time", "id")
R> uu <- tt[,!ind]
R> names(uu) <- rownames(tt)
R> uu
       A.O        B.O        C.O        D.O        E.O        A.P        B.P 
0.26550866 0.37212390 0.57285336 0.90820779 0.20168193 0.89838968 0.94467527 
       C.P        D.P        E.P        A.Q        B.Q        C.Q        D.Q 
0.66079779 0.62911404 0.06178627 0.20597457 0.17655675 0.68702285 0.38410372 
       E.Q        A.R        B.R        C.R        D.R        E.R        A.S 
0.76984142 0.49769924 0.71761851 0.99190609 0.38003518 0.77744522 0.93470523 
       B.S        C.S        D.S        E.S 
0.21214252 0.65167377 0.12555510 0.26722067 

HTH.

Cheers,

	Berwin

=========================== Full address =============================
Berwin A Turlach                            Tel.: +65 6516 4416 (secr)
Dept of Statistics and Applied Probability        +65 6516 6650 (self)
Faculty of Science                          FAX : +65 6872 3919       
National University of Singapore     
6 Science Drive 2, Blk S16, Level 7          e-mail: statba at nus.edu.sg
Singapore 117546                    http://www.stat.nus.edu.sg/~statba
Use the 'reshape' package:
library(reshape)
melt(m)
X1 X2      value
1   A  O 0.26550866
2   B  O 0.37212390
3   C  O 0.57285336
4   D  O 0.90820779
5   E  O 0.20168193
6   A  P 0.89838968
7   B  P 0.94467527
8   C  P 0.66079779
9   D  P 0.62911404
10  E  P 0.06178627
11  A  Q 0.20597457
12  B  Q 0.17655675
13  C  Q 0.68702285
14  D  Q 0.38410372
15  E  Q 0.76984142
16  A  R 0.49769924
17  B  R 0.71761851
18  C  R 0.99190609
19  D  R 0.38003518
20  E  R 0.77744522
21  A  S 0.93470523
22  B  S 0.21214252
23  C  S 0.65167377
24  D  S 0.12555510
25  E  S 0.26722067

Say I have:

set.seed( 1 )
m <- matrix( runif(5^2), nrow=5, dimnames = list( c("A","B","C","D","E"),
c("O","P","Q","R","S") ) )
m
? ? ? ? ?O ? ? ? ? ?P ? ? ? ? Q ? ? ? ? R ? ? ? ? S
A 0.2655087 0.89838968 0.2059746 0.4976992 0.9347052
B 0.3721239 0.94467527 0.1765568 0.7176185 0.2121425
C 0.5728534 0.66079779 0.6870228 0.9919061 0.6516738
D 0.9082078 0.62911404 0.3841037 0.3800352 0.1255551
E 0.2016819 0.06178627 0.7698414 0.7774452 0.2672207

-------------------------------------------------------------------------------------------

I want to create a vector v from matrix m that looks like this:

A.O 0.2655087
B.O 0.3721239

v <- as.vector( m ) almost gives me what I want, but then I need to take
combinations of colnames( m ) and rownames( m ) to get my labels and hope
they match up in order: if not, manipulate the order. ?This approach feels
kludgy...

Is this the right approach or is there a better way?

--
View this message in context: http://www.nabble.com/Converting-a-Matrix-to-a-Vector-tp22696267p22696267.html
Sent from the R help mailing list archive at Nabble.com.

______________________________________________
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.

Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?
try also

m <- matrix( runif(5^2), nrow=5, dimnames = Names<- list(
c("A","B","C","D","E"),
 c("O","P","Q","R","S") ) )

data.frame(expand.grid(Names[[1]],Names[[2]]),as.numeric(m))
data.frame(code=outer(Names[[1]],Names[[2]],paste,sep=".")[1:25],num=as.numeric(m))

Patrizio

2009/3/25 jim holtman <jholtman at gmail.com>:
Use the 'reshape' package:

library(reshape)
melt(m)
? X1 X2 ? ? ?value
1 ? A ?O 0.26550866
2 ? B ?O 0.37212390
3 ? C ?O 0.57285336
4 ? D ?O 0.90820779
5 ? E ?O 0.20168193
6 ? A ?P 0.89838968
7 ? B ?P 0.94467527
8 ? C ?P 0.66079779
9 ? D ?P 0.62911404
10 ?E ?P 0.06178627
11 ?A ?Q 0.20597457
12 ?B ?Q 0.17655675
13 ?C ?Q 0.68702285
14 ?D ?Q 0.38410372
15 ?E ?Q 0.76984142
16 ?A ?R 0.49769924
17 ?B ?R 0.71761851
18 ?C ?R 0.99190609
19 ?D ?R 0.38003518
20 ?E ?R 0.77744522
21 ?A ?S 0.93470523
22 ?B ?S 0.21214252
23 ?C ?S 0.65167377
24 ?D ?S 0.12555510
25 ?E ?S 0.26722067

On Wed, Mar 25, 2009 at 3:13 AM, Ken-JP <kfmfe04 at gmail.com> wrote:
Say I have:

set.seed( 1 )
m <- matrix( runif(5^2), nrow=5, dimnames = list( c("A","B","C","D","E"),
c("O","P","Q","R","S") ) )
m
? ? ? ? ?O ? ? ? ? ?P ? ? ? ? Q ? ? ? ? R ? ? ? ? S
A 0.2655087 0.89838968 0.2059746 0.4976992 0.9347052
B 0.3721239 0.94467527 0.1765568 0.7176185 0.2121425
C 0.5728534 0.66079779 0.6870228 0.9919061 0.6516738
D 0.9082078 0.62911404 0.3841037 0.3800352 0.1255551
E 0.2016819 0.06178627 0.7698414 0.7774452 0.2672207

-------------------------------------------------------------------------------------------

I want to create a vector v from matrix m that looks like this:

A.O 0.2655087
B.O 0.3721239

v <- as.vector( m ) almost gives me what I want, but then I need to take
combinations of colnames( m ) and rownames( m ) to get my labels and hope
they match up in order: if not, manipulate the order. ?This approach feels
kludgy...

Is this the right approach or is there a better way?

--
View this message in context: http://www.nabble.com/Converting-a-Matrix-to-a-Vector-tp22696267p22696267.html
Sent from the R help mailing list archive at Nabble.com.

______________________________________________
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.

--
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?

______________________________________________
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.