From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 26028 invoked by alias); 8 Nov 2003 14:21:39 -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 26020 invoked from network); 8 Nov 2003 14:21:38 -0000 Received: from unknown (HELO aristoteles.physics.uoc.gr) (147.52.180.100) by sources.redhat.com with SMTP; 8 Nov 2003 14:21:38 -0000 Received: from wanadoo.fr (tsirwnis-guest.physics.uoc.gr [147.52.180.217]) by aristoteles.physics.uoc.gr (8.12.10/8.12.10) with ESMTP id hA8ELZlI017034 for ; Sat, 8 Nov 2003 16:21:36 +0200 (EET) Message-ID: <3FACFBEF.2050502@wanadoo.fr> Date: Sat, 08 Nov 2003 14:21:00 -0000 From: Jerome BENOIT Reply-To: jgmbenoit@wanadoo.fr Organization: UOC User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.0) Gecko/20020623 Debian/1.0.0-0.woody.1 MIME-Version: 1.0 To: gsl-discuss@sources.redhat.com Subject: Re: GSL 1.4: BUG #8 [rk8pd.c] References: <1068274810.1218.19.camel@lehrin.local.spaceroots.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-SW-Source: 2003-q4/txt/msg00055.txt.bz2 M Joonas Pihlaja wrote: > On Sat, 8 Nov 2003, Luc Maisonobe wrote: > > [snip] > >>Despite I think nobody is interested anymore, I promised to check the >>coefficients of the method, so here are my results. > > > I'm interested, at least, so thank you for sharing. I am still interested because I currently using it: the rk4 series did not pass my test whereas the rk8pd passed it. Note that my test is rather specific to what I am doing: the test just checks the conservstion of one quatity (namely the energy). Nevertheless I was confused by the BUG report, hence my email to gsl-discuss. So any precision is welcome. > > >>The maximal error in rk8pd.c is about 3.92e-17. >>The maximal error in rksuite.f is about 4.49e-29. > > > What do you mean by maximal error here -- of the main estimator > itself or the second embeded estimator? And how do you compute > these -- from the principal error function or some other method? > I'm very curious, because you say the results for the > coefficients are exact after fixing two free parameters. > > Best Regards, > > Joonas Pihlaja > Thanks, Jerome BENOIT