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From |
"Verkuilen, Jay" <JVerkuilen@gc.cuny.edu> |

To |
<statalist@hsphsun2.harvard.edu> |

Subject |
RE: st: RE: Brute force |

Date |
Mon, 16 Mar 2009 18:53:10 -0400 |

I agree, I think the term "grid search" is much more applicable. Many nonlinear regression programs allow grid search as an option (and rightly so). Using initial values, iteration limits and some for loops, it should be possible to do this in Stata without too much trouble. JV -----Original Message----- From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Maarten buis Sent: Monday, March 16, 2009 4:53 PM To: statalist@hsphsun2.harvard.edu Subject: Re: st: RE: Brute force --- 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/ ----------------------------------------- * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/ * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**References**:**Re: st: RE: Brute force***From:*David Airey <david.airey@vanderbilt.edu>

**Re: st: RE: Brute force***From:*Maarten buis <maartenbuis@yahoo.co.uk>

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