From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 5809 invoked by alias); 6 Aug 2002 17:42:59 -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 5776 invoked from network); 6 Aug 2002 17:42:57 -0000 Received: from unknown (HELO cmailm4.svr.pol.co.uk) (195.92.193.211) by sources.redhat.com with SMTP; 6 Aug 2002 17:42:57 -0000 Received: from modem-85.dorthonion.dialup.pol.co.uk ([62.136.157.85] helo=localhost) by cmailm4.svr.pol.co.uk with esmtp (Exim 3.35 #1) id 17c8M0-0002d5-00; Tue, 06 Aug 2002 18:42:46 +0100 Received: by network-theory.co.uk via sendmail from stdin id (Debian Smail3.2.0.102) for gsl-discuss@sources.redhat.com; Mon, 5 Aug 2002 23:21:59 +0100 (BST) From: Brian Gough MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <15694.64134.858729.222884@debian> Date: Tue, 06 Aug 2002 10:42:00 -0000 To: Di Xiao Cc: Slaven Peles , Subject: Re: Questions on bsimp In-Reply-To: References: X-SW-Source: 2002-q3/txt/msg00102.txt.bz2 Di Xiao writes: > However, I still have a question. We use adaptive stepzie control > because we want to deduce the computational effort. The algorithm > should be smart to know at which region there is the smooth > uninteresting curve, while in some region many small steps are > needed. My question is why bsimp chose some unreasonably big steps > in my code. It can jump from one period to another period without > showing the details of each one. If you run the code, you will > find from the results givin by bsimp, it is hard to tell what > function it likes. I tried different gsl_odeiv_control, but none of > them gave me good results. I guess the reason is when there are > oscillations, bsimp is not a good one. Can anybody explain it? Bsimp can take very large steps and still be highly accurate. See the reference to the paper in the manual for details.