From: Alex Nu <notulei_at_yahoo.com>

Date: Thu 01 Jul 2004 - 23:46:28 EST

R-help@stat.math.ethz.ch mailing list

https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Thu Jul 01 23:52:26 2004

Date: Thu 01 Jul 2004 - 23:46:28 EST

Hi all,

I wonder if this kind of questions are ok in this list...

Quick question:

What does it mean than the rank of the QR decomposition of a NxN matrix is N-1 ?

m: NxN matrix

qr(m)$rank equal to (N-1)

Long version:

I'm doing a manova on a matrix of 10 variables
and 16 observations.

*> dim(tmp)
*

[1] 16 10

*> fit <- manova( tmp ~ treatment*mouse )
*

*>results <- summary(fit,test="Wilks")
*

...

residuals have rank 9 < 10

So the QR decomposition returns with a rank of 9. What does this mean ?

Does this necessarily mean a linear dependency among the columns of the matrix ?

Thanks

Alex

R-help@stat.math.ethz.ch mailing list

https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Thu Jul 01 23:52:26 2004

*
This archive was generated by hypermail 2.1.8
: Fri 18 Mar 2005 - 08:54:48 EST
*