From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 16450 invoked by alias); 18 Mar 2010 18:28:13 -0000 Received: (qmail 16440 invoked by uid 22791); 18 Mar 2010 18:28:13 -0000 X-SWARE-Spam-Status: No, hits=-0.0 required=5.0 tests=AWL,BAYES_50 X-Spam-Check-By: sourceware.org Received: from mx2.oit.ohio.edu (HELO mx2.oit.ohio.edu) (132.235.51.19) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Thu, 18 Mar 2010 18:28:04 +0000 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: ApsEAJQNokuE6wiX/2dsb2JhbACcIKxIDoR8iFuEeQQ Received: from oak3a.cats.ohiou.edu (HELO oak.cats.ohiou.edu) ([132.235.8.151]) by smtpout2.oit.ohio.edu with ESMTP; 18 Mar 2010 14:28:02 -0400 Received: from bubbles.hooperlab (crab-lab.zool.ohiou.edu [132.235.227.198]) (authenticated bits=0) by oak.cats.ohiou.edu (8.13.1/8.13.1) with ESMTP id o2IIRGsR1689985 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Thu, 18 Mar 2010 14:27:17 -0400 (EDT) Message-ID: <4BA2707F.50105@ohiou.edu> Date: Thu, 18 Mar 2010 18:28:00 -0000 From: "Kevin H. Hobbs" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.8) Gecko/20100301 Fedora/3.0.3-1.fc11 Thunderbird/3.0.3 MIME-Version: 1.0 To: gsl-discuss@sourceware.org Subject: ODE IV Control and Variable Scale Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigC0A09017A630E76C0E2AD6CC" 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: 2010-q1/txt/msg00062.txt.bz2 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigC0A09017A630E76C0E2AD6CC Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-length: 999 I'm trying make sure that I am using the gsl_odeiv_control functions correctly. I'm modelling neurons and my variables have different scales. Voltage is usually between -100 and 50 mV. The membrane current gating variables stay between 0 and 1. Internal calcium concentration is usually between 0 and a few hundred micro molar. Each time I read the descriptions of the gsl_odeiv_control functions I become more convinced that the parameters eps_rel, a_y, and a_dydt are there to excuse some error in variables and derivatives that are far from zero. Is that correct? Since I have no reason to care more about values close to zero (unless I do some complicated remapping of the variable values) should I set eps_rel, a_y, and a_dydt to 0? Since my variables have different ranges should I use gsl_odeiv_control_scaled_new with an appropriate eps_abs and scale_abs set with something like 1 for internal calcium concentration, 0.3 for membrane voltage, and 0.001 for all of the gating variables? --------------enigC0A09017A630E76C0E2AD6CC Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" Content-length: 252 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org/ iD8DBQFLonCEqBtEuW+gRPERAnYXAJkB/bIzTcMFiP4Zt2TG38mjLSOIbACfeomc WKCC6AXTXl99eEeMpcjanEo= =OULU -----END PGP SIGNATURE----- --------------enigC0A09017A630E76C0E2AD6CC--