From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gsl-discuss-return-5319-listarch-gsl-discuss=sources.redhat.com@sourceware.org>
Received: (qmail 31140 invoked by alias); 21 Aug 2008 17:47:26 -0000
Received: (qmail 20853 invoked by uid 22791); 21 Aug 2008 17:36:00 -0000
X-Spam-Check-By: sourceware.org
Message-ID: <48ADA750.8030500@lrz.de>
Date: Thu, 21 Aug 2008 17:47:00 -0000
From: bader-reinhold@t-online.de (Reinhold Bader)
Reply-To: Bader@lrz.de
User-Agent: Thunderbird 2.0.0.14 (X11/20080421)
MIME-Version: 1.0
To: gsl-discuss@sourceware.org
CC: Brian Gough <bjg@network-theory.co.uk>
Subject: Documentation
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
X-ID: EkIUOeZQrh7Iwrf6wJhZv9u-AjccBHkyBvXxOIT5Uf1jA9YMZp4zLc1FZabxTFqwCc
X-TOI-MSGID: 233786a8-0aa9-4aff-b5a4-9d01c72abea1
Mailing-List: contact gsl-discuss-help@sourceware.org; run by ezmlm
Precedence: bulk
List-Id: <gsl-discuss.sourceware.org>
List-Subscribe: <mailto:gsl-discuss-subscribe@sourceware.org>
List-Archive: <http://sourceware.org/ml/gsl-discuss/>
List-Post: <mailto:gsl-discuss@sourceware.org>
List-Help: <mailto:gsl-discuss-help@sourceware.org>, <http://sourceware.org/ml/#faqs>
Sender: gsl-discuss-owner@sourceware.org
X-SW-Source: 2008-q3/txt/msg00019.txt.bz2

  Hello,

    the routine fgsl_linalg_QR_update appears to be incorrectly documented.
    Comments in the source as well as my own testing says that the update
    formula is

     Q'R' = Q ( R + w v^T )

    and not Q'R' = Q R + w v^T, as the 1.10 manual presently says.

Regards


-- 
  Dr. Reinhold Bader

  Leibniz-Rechenzentrum, Abt. Hochleistungssysteme | Tel. +49 89 35831 8825
  Boltzmannstr. 1, 85748 Garching                  | Fax  +49 89 35831 9700