From help-request at octave dot org Sat Apr 15 16:40:17 2006 Subject: Re: chol? From: To: Vic Norton , Octave Help Date: Sat, 15 Apr 2006 17:35:44 -0400 Here is what I get GNU Octave, version 2.1.73 (i686-pc-cygwin). Copyright (C) 2006 John W. Eaton. This is free software; see the source code for copying conditions. There is ABSOLUTELY NO WARRANTY; not even for MERCHANTIBILITY or FITNESS FOR A PARTICULAR PURPOSE. For details, type `warranty'. Additional information about Octave is available at http://www.octave.org. Please contribute if you find this software useful. For more information, visit http://www.octave.org/help-wanted.html Report bugs to (but first, please read http://www.octave.org/bugs.html to learn how to write a helpful report). octave:1> C = [36 24; 24 25]; octave:2> C C = 36 24 24 25 octave:3> octave:3> chol(C) ans = 6 4 0 3 Upper Triangular Doug Stewart > > From: Vic Norton > Date: 2006/04/15 Sat PM 04:16:22 EST > To: Octave Help > Subject: chol? > > I had thought Octave, version 2.1.73, was working fine on my iMac G5, > but now I'm not so sure. Here's my problem. > > I start with the matrix > octave> C = [36 24; 24 25]; > and do > octave> chol(C); > After waiting for a while I get > panic: Bus error -- stopping myself... > attempting to save variables to `octave-core'... > save to `octave-core' complete > Bus error > vic$ > > To tell you the truth I'm not sure what the Cholesky factor of C is > supposed to be. I do know that C = R' * R where > R = [0 3; 6 4]. > I have no problem computing another R that does this job: > octave> C = [36 24; 24 25]; > octave> [U, S, V] = svd(C); > octave> R = sqrt(S) * V'; > Now > R = [ > -5.8067 -4.6265 > -1.5108 1.8962 > ] > and C = R' * R for this R as well. But R = chol(C) simply doesn't work > for me. > > Is anybody else having any problems with "chol" or is it just my screwed > up system? > > Regards, > > Vic > > > > ------------------------------------------------------------- > 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 > ------------------------------------------------------------- > ------------------------------------------------------------- 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 -------------------------------------------------------------