From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 21342 invoked by alias); 20 Feb 2007 09:14:28 -0000 Received: (qmail 21231 invoked by uid 22791); 20 Feb 2007 09:14:26 -0000 X-Spam-Check-By: sourceware.org Received: from atb104.slac.stanford.edu (HELO atb104.slac.stanford.edu) (134.79.37.104) by sourceware.org (qpsmtpd/0.31) with ESMTP; Tue, 20 Feb 2007 09:14:19 +0000 Received: from atb104.slac.stanford.edu (atb104 [127.0.0.1]) by atb104.slac.stanford.edu (8.13.8/8.13.8) with ESMTP id l1K9EGk2010058; Tue, 20 Feb 2007 01:14:16 -0800 Received: (from fenn@localhost) by atb104.slac.stanford.edu (8.13.8/8.13.8/Submit) id l1K9EFJN010057; Tue, 20 Feb 2007 01:14:15 -0800 Date: Tue, 20 Feb 2007 09:14:00 -0000 From: Tim Fenn To: Brian Gough Cc: gsl-discuss@sourceware.org Subject: Re: test release gsl-1.8.90.tar.gz Message-ID: <20070220091414.GA10049@stanford.edu> References: <873b57h9dg.wl%bjg@network-theory.co.uk> <20070216080934.GA28153@stanford.edu> <87y7mxpzg5.wl%bjg@network-theory.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87y7mxpzg5.wl%bjg@network-theory.co.uk> X-PGP-Key: http://www.stanford.edu/~fenn/gpg-public-key.asc User-Agent: Mutt/1.5.12-2006-07-14 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: 2007-q1/txt/msg00035.txt.bz2 On Fri, Feb 16, 2007 at 09:25:30PM +0000, Brian Gough wrote: > At Fri, 16 Feb 2007 00:09:34 -0800, > Tim Fenn wrote: > > I've been testing the bfgs2 minimizer, and it works well until/if it > > nears a point in which the interpolator stops progressing - I've > > noticed there is a check against this in the linear_minimize code near > > line 209: > > > > if ((a-alpha)*fpa <= GSL_DBL_EPSILON) { > > /* roundoff prevents progress */ > > }; > > > > perhaps there should be a break statement to prevent futile > > iterations? Or use this as a stopping criteria test? > > Thanks, there should be a > > return GSL_ENOPROG; > > in there. You might want to try that and see if it stops at an > acceptable place. That helps, yes. It also might be worthwhile to note the bfgs2 minimizer requires positive step_size values (which makes intuitive sense, but is not true of the bfgs/cgpr/cgfr minimizers). Regards, Tim -- --------------------------------------------------------- Tim Fenn fenn@stanford.edu Stanford University, School of Medicine James H. Clark Center 318 Campus Drive, Room E300 Stanford, CA 94305-5432 Phone: (650) 736-1714 FAX: (650) 736-1961 ---------------------------------------------------------