backsolve... --> class()es for special matrices ?

[Jonathan Rougier]

  This message is in MIME format.  The first part should be readable text,
  while the remaining parts are likely unreadable without MIME-aware tools.
  Send mail to mime@docserver.cac.washington.edu for more info.

---559023410-1902445306-917000089=:29339
Content-Type: TEXT/PLAIN; charset=US-ASCII

Hi Martin,

I attach my versions of solve methods for triangular and variance
matrices.  The triangular method is a wrapper for backsolve() which
allows both a trans flag and a right flag (ie giving the four different
solves that you alluded to).  The variance method uses a cholesky
decomposition and then two triangular solves (one with the trans flag
set), as recommended by Golub and van Loan.  I have taken care with the
returning vector/matrix, as in the backsolve() patch!

I was not in on the previous Matrix class discussion.  I use them in
Splus, but from a purely aesthetic point of view I don't like the idea
that R would need a Matrix add-on.  I think I would rather see the
appropriate methods built into the base. 

Cheers, Jonathan.

Jonathan Rougier                       Science Laboratories
Department of Mathematical Sciences    South Road
University of Durham                   Durham DH1 3LE

"[B]egin upon the precept ... that the things we see are to be 
 weighed in the scale with what we know"  (Meredith, 1879, The Egoist)

---559023410-1902445306-917000089=:29339
Content-Type: APPLICATION/octet-stream; name="solve.tar.gz"
Content-Transfer-Encoding: BASE64
Content-ID: <Pine.GSO.3.96.990122101449.29339R@laplace>
Content-Description: 
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---559023410-1902445306-917000089=:29339--
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
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: r-devel-request@stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._