From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 27450 invoked by alias); 12 Aug 2003 15:24:32 -0000 Mailing-List: contact gsl-discuss-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gsl-discuss-owner@sources.redhat.com Received: (qmail 27436 invoked from network); 12 Aug 2003 15:24:31 -0000 Received: from unknown (HELO red.csi.cam.ac.uk) (131.111.8.70) by sources.redhat.com with SMTP; 12 Aug 2003 15:24:31 -0000 Received: from polaris.eng.cam.ac.uk ([129.169.154.83] helo=hermes.cam.ac.uk) by red.csi.cam.ac.uk with esmtp (Exim 4.12) id 19mb0h-0000FO-00; Tue, 12 Aug 2003 16:24:31 +0100 Message-ID: <3F3909AE.5030703@hermes.cam.ac.uk> Date: Tue, 12 Aug 2003 15:24:00 -0000 From: Adam Johansen User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4a) Gecko/20030401 X-Accept-Language: en, en-us MIME-Version: 1.0 To: GSL Subject: Re: Vector cross product References: <3F37A0EC.9030103@ido.org> <16184.51091.526969.628064@debian.local> <3F3905E3.50801@ido.org> In-Reply-To: <3F3905E3.50801@ido.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-SW-Source: 2003-q3/txt/msg00137.txt.bz2 Haisam K. Ido wrote: > > Agreed that it's simple, but the dot product is even simpler and is > included with GSL/BLAS. Even a*A[][] is included (a is a scalar) > which is even simpler than the dot product! > I think the point which Brian was trying to make -- and I apologise in advance if I'm wrong -- is that a dot product is general and applies to vectors of any length as the sum of the pairwise products of the elements of those vectors. In contrast, the vector product you're referring to only exists when the vector is of length three. As such it's a specialised case and not worth including in the library. Adam