Path: news.mathworks.com!not-for-mail
From: "Bruno Luong" <b.luong@fogale.findmycountry>
Newsgroups: comp.soft-sys.matlab
Subject: Re: random matrix generation
Date: Mon, 9 Nov 2009 07:31:03 +0000 (UTC)
Organization: FOGALE nanotech
Lines: 40
Message-ID: <hd8gfn$dkn$1@fred.mathworks.com>
References: <5b29b80c-64b8-47cc-bc93-493bb9591d42@r5g2000yqb.googlegroups.com> <8a05888a-f76b-4565-992d-802d92ce953e@v30g2000yqm.googlegroups.com>
Reply-To: "Bruno Luong" <b.luong@fogale.findmycountry>
NNTP-Posting-Host: webapp-05-blr.mathworks.com
Content-Type: text/plain; charset="ISO-8859-1"
Content-Transfer-Encoding: 8bit
X-Trace: fred.mathworks.com 1257751863 13975 172.30.248.35 (9 Nov 2009 07:31:03 GMT)
X-Complaints-To: news@mathworks.com
NNTP-Posting-Date: Mon, 9 Nov 2009 07:31:03 +0000 (UTC)
X-Newsreader: MATLAB Central Newsreader 390839
Xref: news.mathworks.com comp.soft-sys.matlab:583481


arun <aragorn168b@gmail.com> wrote in message <8a05888a-f76b-4565-992d-802d92ce953e@v30g2000yqm.googlegroups.com>...
> On Nov 8, 12:49?am, ImageAnalyst <imageanal...@mailinator.com> wrote:
> > On Nov 7, 5:18?pm, arun <aragorn1...@gmail.com> wrote:
> >
> > > hi,
> >
> > > how can i generate a m*nmatrixwith the m-rows
> > > 1) dependent on each other
> > > 2) independent of each other
> >
> > > also, is it possible to create the samerandommatrixwith just 1's
> > > and 0's under the same 2 criterias?
> >
> > > thank you,
> > > best, arun.
> >
> > --------------------------------------------------------------------
> > 1) depends on what you mean by dependent.
> > 2) ?randomArray = rand(100, 50);
> >
> > binaryRandomArray = randomArray > 0.5;
> 
> what i mean by independent is that, if I take any 2 rows and compute a
> measure of dependence (say, corr), and then permute one of the rows
> and compute *corr* a 1000 times and obtain its distribution, then they
> should be that of a uniform distribution's pdf (equally likely). Or,
> equivalently, the cdf of p-values obtained directly from corr should
> be that of a uniform distribution's pdf.
> 
> if its not, they are dependent in some way.
> best, arun.

1. Dependent
epsilon = 0.1
A = ones(100,50)+epsilon*randn(100,50)

2. Independent
A = randn(100,50)

Bruno