help-octave
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Is A\b using a sparse solver if A is sparse?


From: LUK ShunTim
Subject: Re: Is A\b using a sparse solver if A is sparse?
Date: Thu, 02 Feb 2006 13:16:09 +0800
User-agent: Debian Thunderbird 1.0.7 (X11/20051017)

Geordie McBain wrote:
> 2.1.x doesn't have the new sparse implementation; it's only in 2.9.x.
> For 2.9, the sparse implementation is in Octave proper rather than
> Octave Forge.
> 
> There is a debian package for octave2.9.

yes, thanks. But still similar result. :-(

<diary>
octave2.9:3> A=sprand(2500,2500,0.03);
octave2.9:4> b=eye(2500,1);
octave2.9:5> r=A*b;
octave2.9:6> fullA=full(A);
octave2.9:7> tic;A\r;toc
ans = 25.196
octave2.9:8> tic;A\r;toc
ans = 12.622
octave2.9:9> tic;A\r;toc
ans = 14.420
octave2.9:10> tic;A\r;toc
ans = 12.125
octave2.9:11> tic;A\r;toc
ans = 12.117
octave2.9:12> tic;fullA\r;toc
ans = 6.6568
octave2.9:13> tic;fullA\r;toc
ans = 5.1657
octave2.9:14> tic;fullA\r;toc
ans = 5.1253
octave2.9:15> tic;fullA\r;toc
ans = 5.1157
</diary>

Regards,
ST
--



-------------------------------------------------------------
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
-------------------------------------------------------------



reply via email to

[Prev in Thread] Current Thread [Next in Thread]