gnumeric-list-request gnome org wrote:
According to the microsoft web site, Solver in Excel uses the "Generalized Reduced Gradient Algorithm". The solver plugin is written by Frontline Systems (www.solver.com)Date: Thu, 26 Mar 2009 11:12:55 -0600 From: "Andreas J. Guelzow" <aguelzow math concordia ab ca> Subject: Re: gnumeric-list Digest, Vol 59, Issue 21 According to the Gnumeric solver dialog, the solver uses a simplex algorithm to optimize the function. I really don't think that is the right tool for your kind of problem. Which kind of algorithm is used by OpenOffice Calc and/or Excel? The Solver for Nonlinear Programming extension for OpenOffice consists of two independent algorithms: Differential Evolution and Particle Swarm Optimization. For more information see: http://wiki.services.openoffice.org/wiki/NLPSolver Well Andreas, I certainly respect your academic skepticism. Indeed, there is no reason to either accept or doubt my claim. Rather, I encourage you to check the veracity of my report yourself (presuming you have access to a computer with excel). The article and the spreadsheet are available on line at http://sportsci.org/2009/sjejcm.htm Once you go the article, you will see a link to the spreadsheet. So please feel free (indeed obligated by your publicly stated doubt of my report) to download that spreadsheet, set the Fourier coefficients to some new values, and then run solver yourself. Please let us know how quickly it converges for you. When I reset the coefficients for the 1st order approximation to zero solver finds the solution almost instantaneously. Perhaps that is somehow related to the fact that solver has done the approximation before on my computer and has access to that solution history. So please try it from scratch on your computer.(I doubt that there is a general solver that will "converge in seconds" for an arbitrary problem.) Sincerely, Jim -- James C. Martin PhD Associate Professor The Neuromuscular Function Lab Department of Exercise and Sport Science College of Health The University of Utah 250 S. 1850 E. Room 241 Salt Lake City, Utah, 84112-0920 Voice 801-587-7704 Fax 801-585-3992 http://www.health.utah.edu/ess/people/martin.html "The best way to have a good idea is to have a lot of ideas." Linus Pauling |