Without an example, I'm not sure how much help I can be. Does your Variogram calculation return a single value that could be minimized? Or could it be coerced to be so?
I would suggest, if you haven't done so, a look at ?nlm and ?nlminb. Alternatively, the CRAN package 'optimx' serves as a wrapper to many optimization algorithms and offers methods to compare them side-by-side. Good luck, Jon -------------------------------------- Jonathan P. Daily Technician - USGS Leetown Science Center 11649 Leetown Road Kearneysville WV, 25430 (304) 724-4480 "Is the room still a room when its empty? Does the room, the thing itself have purpose? Or do we, what's the word... imbue it." - Jubal Early, Firefly r-help-boun...@r-project.org wrote on 12/20/2010 09:39:49 AM: > [image removed] > > [R] How to optimize function parameters? > > zbynek.jano...@gmail.com > > to: > > r-help > > 12/20/2010 10:43 AM > > Sent by: > > r-help-boun...@r-project.org > > > Hi, > > I have a dataset and I want to fit a function to it. > The function is variogram model (http://en.wikipedia.org/wiki/Variogram) > The variogram model is defined by three parameters and I want them to be > automatically optimized for real time data. > I tried to use gafit {gafit} for this, but there are some data > configuration, where optimal results given by gafit() are negative, which is > not correct and cannot be used for further calculating. gafit() does not > enable me to set a range of possible results (at least I did not succeded in > doing so), therefore I am looking for another solution (Powell´s gradient > descent possibly?). > > Can anyone give me a hint where to look? > > Thanks > > Zbynek > -- > View this message in context: http://r.789695.n4.nabble.com/How-to- > optimize-function-parameters-tp3095603p3095603.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.