Newsgroups: comp.lang.apl
Path: watmath!watserv2.uwaterloo.ca!torn!howland.reston.ans.net!usc!elroy.jpl.nasa.gov!ames!olivea!hal.com!decwrl!csus.edu!sfsuvax1.sfsu.edu!vpcsc4
From: vpcsc4@sfsuvax1.sfsu.edu (Emmett McLean)
Subject: Re: Question: Tri-diagonal matrices in APL
Message-ID: <1993May8.184458.10957@csus.edu>
Sender: news@csus.edu
Organization: San Francisco State University
References: <1695@kepler1.rentec.com> <1993May6.030445.3577@csus.edu> <1697@kepler1.rentec.com>
Date: Sat, 8 May 1993 18:44:58 GMT
Lines: 17

In article (Andrew Mullhaupt) writes:
>
>Well then what is the indigenous inversion? Is it something reasonable
>like Householder QR with column pivoting (as in APL2) or is it something
>to be avoided like straight Gaussian elimination. I would tend toward
>using Chan style (or Lawson-Hanson, depending on attribution) R-SVD, but
>Householder QR with column pivoting should do a decent job.

 Upon reveiwing the documentation, I see J uses a QR method.
 A substantial amount of amending goes on so my best guess
 is that column pivoting is used.

>
>Later,
>Andrew Mullhaupt


