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Message-ID: <41585A21.2050507@kimvdlinde.com>
Date: Mon, 27 Sep 2004 14:21:21 -0400
From: Kim van der Linde <kim@kimvdlinde.com>
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To: Jakarta Commons Developers List <commons-dev@jakarta.apache.org>
Subject: Re: [math] API changes for RC2
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Phil Steitz wrote:

> "Spooky" -- delightful word choice ;-)  The getDataRef  method is
> there to limit copy operations and to support hacking the underlying
> array -- evil, hazardous, breaks encapsulation -- altogether
> "spooky"; but users may want this in some cases.

I do:

Matrix diffMatrix = new Matrix(cases, variables);
double diffArray[][] = diffMatrix.getDataRef();
double baseArray[][] = baseMatrix.getDataRef();
//verbose(true, "Robust baseMatrix\n"+baseMatrix.toSquareString());
for (int x = 0; x < cases; x++)
{
   for (int y = 0; y < variables; y++)
   {
     diffArray[x][y] = baseArray[x][y] - robustMeans[y];
   }
}
//verbose(true, "Robust diffArray\n"+diffMatrix.toSquareString());
robustDist = Distances.mahalanobis(diffMatrix, robustCovar);
det = Math.sqrt(robustCovar.getDeterminant());

Just an example.......

Kim

-- 
http://www.kimvdlinde.com

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