Subject: Re: chol() dimnames
From: Prof Brian Ripley (email@example.com)
Date: Mon 27 Sep 1999 - 21:25:05 EST
> Date: Mon, 27 Sep 1999 11:18:52 +0100 (BST)
> From: Jonathan Rougier <J.C.Rougier@durham.ac.uk>
> To: firstname.lastname@example.org
> Subject: chol() dimnames
> Hi Everyone,
> Just a minor point, but could chol() be changed to include the dimnames of
> the original matrix? This will ensure that x and t(R) %*% R have the same
> dimnames, where R <- chol(x). So we just need to insert
> if (!is.null(dx <- dimnames(x)))
> dimnames(z$v) <- dx
> ahead of the return. Cheers, Jonathan.
This is a picky comment, but maybe we should try to get this spot on.
(i) Suppose that the row and column names of x are different? Which should
(ii) I don't think that R has any obvious row names: effectively this is
a linear transformation to a different and unamed basis for the space.
I believe all one actually knows is that the colnames of R should be the
colnames of x, if the row and column names of x match. However, the
prototype does preserve the names. Should we just preserve the colnames?
-- Brian D. Ripley, email@example.com 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 272860 (secr) Oxford OX1 3TG, UK Fax: +44 1865 272595
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: firstname.lastname@example.org _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
This archive was generated by hypermail 2b25 : Tue 04 Jan 2000 - 14:16:08 EST