Converting a Matrix to a Vector

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

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