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Re: st: RE: Brute force


From   Maarten buis <maartenbuis@yahoo.co.uk>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: RE: Brute force
Date   Mon, 16 Mar 2009 20:53:05 +0000 (GMT)

--- On Mon, 16/3/09, David Airey wrote:
> This might be what he is asking...?
> 
> http://cran.r-project.org/web/packages/nls2/nls2.pdf

looks like a grid search to me, which would be a 
special case of a "brute force" method. This method
could be useful to assess the sensitivity of your
results to different staring values, which makes
sense with a method like nonlinear least squares.
However, I would only apply it after a regular 
nonlinear least squares estimation (-nl- in Stata).

A different question is whether this method would
deserve its own name. Assigning names to simple
techniques often just add more confusion than 
clarity. In this case you could just write in a
paper "I tried out different starting values and
the results did (not) change". If you insisted 
on calling it the "brute force algorithm", than 
the resuting text would sound more impressive 
but would actually be less clear: "I applied 
the brute force algorithm and the results proved
(not) to be robust"

-- Maarten

-----------------------------------------
Maarten L. Buis
Institut fuer Soziologie
Universitaet Tuebingen
Wilhelmstrasse 36
72074 Tuebingen
Germany

http://home.fsw.vu.nl/m.buis/
-----------------------------------------





      

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