Path: news.mathworks.com!not-for-mail
From: <HIDDEN>
Newsgroups: comp.soft-sys.matlab
Subject: Re: Fast Matrix*Diagonal*Matrix operation
Date: Thu, 3 Feb 2011 20:58:04 +0000 (UTC)
Organization: The MathWorks, Inc.
Lines: 17
Message-ID: <iif4sr$dh0$1@fred.mathworks.com>
References: <ii7d79$lto$1@fred.mathworks.com> <ii8c3b$a9r$1@fred.mathworks.com>
Reply-To: <HIDDEN>
NNTP-Posting-Host: www-00-blr.mathworks.com
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
X-Trace: fred.mathworks.com 1296766684 13856 172.30.248.45 (3 Feb 2011 20:58:04 GMT)
X-Complaints-To: news@mathworks.com
NNTP-Posting-Date: Thu, 3 Feb 2011 20:58:04 +0000 (UTC)
X-Newsreader: MATLAB Central Newsreader 2429683
Xref: news.mathworks.com comp.soft-sys.matlab:707983

Hi Bruno,

Could you explain why it is so? Thanks.

best,

Gongguo
"Bruno Luong" <b.luong@fogale.findmycountry> wrote in message <ii8c3b$a9r$1@fred.mathworks.com>...
> "Gongguo Tang" wrote in message <ii7d79$lto$1@fred.mathworks.com>...
> 
> > 
> > I am wondering if there is any way to obtain Q'*D(t)*Q as fast as possible. Maybe from the result of Q'*Q or some kind of decomposition of Q'*Q?
> > 
> 
> I'm pretty sure the answer is: no, it's not possible.
> 
> Bruno