From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 19579 invoked by alias); 9 Oct 2008 13:22:24 -0000 Received: (qmail 19566 invoked by uid 22791); 9 Oct 2008 13:22:22 -0000 X-Spam-Check-By: sourceware.org Received: from mail.network-theory.co.uk (HELO mail.network-theory.co.uk) (66.199.228.187) by sourceware.org (qpsmtpd/0.31) with ESMTP; Thu, 09 Oct 2008 13:21:46 +0000 Date: Thu, 09 Oct 2008 13:22:00 -0000 Message-ID: From: Brian Gough To: Tuomo Keskitalo Cc: GSL Discuss Mailing List Subject: Re: ode-initval implicit solvers and development In-Reply-To: <48E25CA9.6080306@iki.fi> References: <48E25CA9.6080306@iki.fi> User-Agent: Wanderlust/2.14.0 (Africa) Emacs/22.2 Mule/5.0 (SAKAKI) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII X-Message-Mac: 7c47061bf1f4c5715118ca549ac489c8 Mailing-List: contact gsl-discuss-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gsl-discuss-owner@sourceware.org X-SW-Source: 2008-q4/txt/msg00004.txt.bz2 At Tue, 30 Sep 2008 20:06:49 +0300, Tuomo Keskitalo wrote: > my work with GSL ODE solvers is progressing (slowly, I am doing this on > my own free time). I've written a modified Newton iteration method to > solve the non-linear equation system that come up with implicit > Runge-Kutta methods. Three very basic implicit solvers included use the > solver. Also, I've made some changes and additions to ode-initval tests. This is good, I would like to replace the existing rkimp solvers with these in a future release. The main outstanding change needed is to avoid recomputing the jacobian J(t,x) in the second call to modnewton1_init. The parameters t and x are the same so it computed once in the caller and passed to modnewton1_init as a parameter. -- Brian Gough