yes, there is -- have a look at the online help file ?"[", especially
argument 'drop'. Try also this:
crud <- matrix(c(1,2,3,4,5,6,7,8,9,10,11,12),nrow=3,ncol=4)
crud[, 1, drop = FALSE]
I hope it helps.
Best,
Dimitris
On 4/6/2010 1:39 PM, Robert M. Flight wrote:
Hi All,
I'm hoping someone else can help me out with this. I am doing some
matrix algebra using sub-parts of matrices, and sometimes I need only
a single row/column of the original matrix. However, whenever I pull
out only a single row/column, R returns a row vector, but often this
will break my matrix algebra. Is there any *easy* way to get R to
remember what the single row/column came out of and format the return
appropriately?
Example:
crud<- matrix(c(1,2,3,4,5,6,7,8,9,10,11,12),nrow=3,ncol=4)
tmp<- crud[,1]
#tmp gives: [1] 1 2 3
what I actually want is:
tmp<- crud[,1]
#tmp gives
[,1]
[1,] 1
[2,] 2
[3,] 3
I don't see an easy way to do this beyond using matrix and supplying
the correct matrix dimensions based on the indexing, or using a
conditional to check if only one column/row is being taken out.
Any help would be very much appreciated.
Regards,
-Robert
Robert M. Flight, Ph.D.
Bioinformatics and Biomedical Computing Laboratory
University of Louisville
Louisville, KY
PH 502-852-0467
EM robert.fli...@louisville.edu
EM rfligh...@gmail.com
Williams and Holland's Law:
If enough data is collected, anything may be proven by
statistical methods.
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--
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
______________________________________________
R-help@r-project.org mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
