This is not to do with 'wide' matrices' but to do with the lack of column
names.
There is a bug -- the definition of 'p' should have NROW and not NCOL.
On Sun, 18 May 2008, Gad Abraham wrote:
Hi,
I'm doing PCA on wide matrices and I don't understand why calling
predict.prcomp on it throws an error:
x1 <- matrix(rnorm(100), 5, 20)
x2 <- matrix(rnorm(100), 5, 20)
p <- prcomp(x1)
predict(p, x2)
Error in predict.prcomp(p, x2) :
'newdata' does not have the correct number of columns
dim(x2)
[1] 5 20
dim(p$rotation)
[1] 20 5
All predict.prcomp really does is x2 %*% p$rotation, which is a perfectly
legal operation that should yield a 5x5 matrix:
dim(x2 %*% p$rotation)
[1] 5 5
Thanks,
Gad
--
Gad Abraham
Dept. CSSE and NICTA
The University of Melbourne
Parkville 3010, Victoria, Australia
email: [EMAIL PROTECTED]
web: http://www.csse.unimelb.edu.au/~gabraham
______________________________________________
R-help@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.
--
Brian D. Ripley, [EMAIL PROTECTED]
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
______________________________________________
R-help@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.
