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Re: bandmatrix

  • To: mathgroup at smc.vnet.net
  • Subject: [mg100609] Re: bandmatrix
  • From: "Sjoerd C. de Vries" <sjoerd.c.devries at gmail.com>
  • Date: Tue, 9 Jun 2009 03:55:47 -0400 (EDT)
  • References: <h0id72$lkq$1@smc.vnet.net>

Looks like homework. Do yourself a favor and try to solve it yourself.
You will learn much more in the process.

Cheers -- Sjoerd

On Jun 8, 9:05 am, Prado <josepradom... at yahoo.com.br> wrote:
> Hello, I am a newbie in Mathematica. I need help in the problem:
> reduce the band of a sparse matrix (100 x 100 ) with 10% approximately
> of ones.
> I known that Mathematica has a implementation to do this.(see the
> code)
> Needs["GraphUtilities`"]
> ma=Table[ If[n==m,1,If[RandomInteger[100]<90,0,1]],{n,1,100},{m,
> 1,100}];
> {r,c}=MinimumBandwidthOrdering[ma,Method->"RCM"];
> (* Show Matrices *)
> MatrixPlot[ma,ColorFunction->"Monochrome"]
> MatrixPlot[ma[[r,c]],ColorFunction->"Monochrome"]
> But the problem is: reduce the band of a sparse matrix (about 10% of
> ones) using "simulated annealing" process, without using RCM method or
> Sloam method.
> Implement a program using Mathematica.
> Can someone help me?



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