Re: [R] diagonal matrices
On Sat, 20 Aug 2005, Afshartous, David wrote:
> I have matrices V.i of dimension n.i x n.i, where i = 1, ..., J, and the
> sum of n.i equals N. (and n.i ! = n.j)
>
> goal: create one large matrix V, where V has matrices V.i on diagonal.
>
> I create each matrix V.i in a for loop (1 to J), so each time I'd like
> to augment V with the most recently calculated V.i, such that I'll have
> V after the final iteration of the for loop.
>
> question: how to initialize V and do the augmentation. any advice much
> appreciated.
It is probably best to pre-create a matrix and fill in the blocks. As in
V <- matrix(0, N, N)
# let n be a vector of what you called n.i
n0 <- c(0, cumsum(n))
for(i in 1:J) {
ind <- (n0[i]+1):n0[i+1]
V[ind, ind] <- V.i
}
>
> cheers,
> dave
>
> ps - please respond directly to [EMAIL PROTECTED], thanks!
Please set that as your reply address to ease the lot of your helpers.
--
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, UKFax: +44 1865 272595
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Re: [R] diagonal matrices
Have a look at adiag in the magic package. On 8/20/05, Afshartous, David <[EMAIL PROTECTED]> wrote: > > Hello all, > > I have matrices V.i of dimension n.i x n.i, where i = 1, ..., J, and the > sum of n.i equals N. (and n.i ! = n.j) > > goal: create one large matrix V, where V has matrices V.i on diagonal. > > I create each matrix V.i in a for loop (1 to J), so each time I'd like to > augment V with the > most recently calculated V.i, such that I'll have V after the final iteration > of the for loop. > > question: how to initialize V and do the augmentation. any advice much > appreciated. > > cheers, > dave > > ps - please respond directly to [EMAIL PROTECTED], thanks! > > > >[[alternative HTML version deleted]] > > __ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html > __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
[R] diagonal matrices
Hello all, I have matrices V.i of dimension n.i x n.i, where i = 1, ..., J, and the sum of n.i equals N. (and n.i ! = n.j) goal: create one large matrix V, where V has matrices V.i on diagonal. I create each matrix V.i in a for loop (1 to J), so each time I'd like to augment V with the most recently calculated V.i, such that I'll have V after the final iteration of the for loop. question: how to initialize V and do the augmentation. any advice much appreciated. cheers, dave ps - please respond directly to [EMAIL PROTECTED], thanks! [[alternative HTML version deleted]] __ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
