[R] QR decomposition question
Alex Nu
notulei at yahoo.com
Thu Jul 1 15:46:28 CEST 2004
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
More information about the R-help
mailing list