X-Recipient: archive-cygwin@delorie.com
X-SWARE-Spam-Status: No, hits=-2.0 required=5.0	tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,T_TO_NO_BRKTS_FREEMAIL
X-Spam-Check-By: sourceware.org
Message-ID: <877561.49926.qm@web29017.mail.ird.yahoo.com>
Date: Mon, 3 May 2010 08:39:54 +0000 (GMT)
From: texsit <texsit@yahoo.it>
Subject: Octave 3.2.3: wrong matrix calculation
To: cygwin@cygwin.com
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Transfer-Encoding: quoted-printable
Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm
List-Id: <cygwin.cygwin.com>
List-Subscribe: <mailto:cygwin-subscribe@cygwin.com>
List-Archive: <http://sourceware.org/ml/cygwin/>
List-Post: <mailto:cygwin@cygwin.com>
List-Help: <mailto:cygwin-help@cygwin.com>, <http://sourceware.org/ml/#faqs>
Sender: cygwin-owner@cygwin.com
Mail-Followup-To: cygwin@cygwin.com
Delivered-To: mailing list cygwin@cygwin.com

Hi All,
I use octave 3.2.3 under Cygwin (windows 7) for my math application.=20
I discovered a bad calculation calling the function det(). The step to repr=
oduce is this:

> A =3D [1,2,3;4,5,6;7,8,9];
> det(A)
ans =3D -9.5171e-16

The matrix is singular so I expected the resul was 0 and not a very very li=
ttle number. I problem is the same also with Octave 3.2.4.
At the begin I thougth it was only a round error, but I've made the same pr=
oof with Octave under Debian Linux (lenny).=20
Under Linux=A0the resul has been 0 as I expected.

Can anyone suggest me something to solve that problem?

I'm using Cygwin 1.7.5-1 with Intel centrino 2 and windows 7 64 bit.

Thank you in advance.
Regards.

Luca




--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple