From help-request at octave dot org Tue Feb 28 00:50:26 2006 Subject: Re: Extended precision From: =?ISO-8859-1?Q?Arvid_Ros=E9n?= To: Andy Adler CC: "help at octave dot org" Date: Tue, 28 Feb 2006 07:48:40 +0100 Andy Adler wrote: > On Mon, 27 Feb 2006, Arvid Rosén wrote: > > >> Hi! >> I am frequently working with ill-conditioned state-space systems, and >> the matrix calculations often lead to problems. Are there any ways to >> get increasted or extended precision in Octave? 128-bit doubles or more >> would probably help alot in this case. >> > > I work with ill-conditioned systems for much of my research. > and I would tend to be very suspicious of a statement like that. > > If the underlying problem is ill-conditioned then needing 128-bit > doubles is probably avoiding the real issue, as an algorithm which > is sensitive to rounding in this way has probably diverged long ago. > > I would look into regularization techniques to improve the > conditioning of the algorithms. > > -- > Andy Adler 1(613)562-5800x6218 Thanks Andy! I'll bet you are right here. I was just hoping that someone would tell my about the new HYPER-MEGE-PRECISION-flag in octave-2.9 ;-) I guess I'll have to go and find myself a nice textbook (any recommendations?) on the topic and get started fixing the real problem. /Arvid ------------------------------------------------------------- Octave is freely available under the terms of the GNU GPL. Octave's home on the web: http://www.octave.org How to fund new projects: http://www.octave.org/funding.html Subscription information: http://www.octave.org/archive.html -------------------------------------------------------------