On Aug 4, 2009, at 9:06 PM, Hongwei Dong wrote: > Thanks, David, you are right. If I use continuous data such as 1, > 2, ...6 to represent those 6 housing types, the model works with the > lme function in R. The problem is, the relationship between the 6 > housing types are not continuous, which we assume when we use > 1,2,..6 to represent them.
And that is why you use a factor variable rather than a numeric variable. > > Harry > > > On Tue, Aug 4, 2009 at 5:47 PM, David Winsemius <dwinsem...@comcast.net > > wrote: > > On Aug 4, 2009, at 7:48 PM, Hongwei Dong wrote: > > Yeah, I have a very large sample size, about 60,000 observations. > Multicollinearity should not be a problem here. The weird thing is > that SPSS > can converge very quickly and gives out reasonable results. > The only problem I can think of is that, my first level (random) > variables > are dummy variables: 6 housing types, and I used five dummies in > model and > one as the reference. I also tried to combine them into two groups > and use > only dummy at random level, but it does not work either. > > is there any one here has similar experience with the LME function > in R? > > I have absolutely no experience with "LME" but I can predict with > very high probability that you would be getting more sensible result > if you modeled those housing types with a single factor variable > rather than creating 6 dummies. ((Would one generally not create a > reference dummy?) > > ?factor > > -- > David. > > > > Thanks. > > Harry > > > > On Tue, Aug 4, 2009 at 1:28 AM, ONKELINX, Thierry > <thierry.onkel...@inbo.be>wrote: > > Dear Harry, > > Your model seems rather complex. Do you have enough data to support > it? > Did you check for multicollinearity between the variables? > > HTH, > > Thierry > > > > ------------------------------------------------------------------------ > ---- > ir. Thierry Onkelinx > Instituut voor natuur- en bosonderzoek / Research Institute for Nature > and Forest > Cel biometrie, methodologie en kwaliteitszorg / Section biometrics, > methodology and quality assurance > Gaverstraat 4 > 9500 Geraardsbergen > Belgium > tel. + 32 54/436 185 > thierry.onkel...@inbo.be > www.inbo.be > > To call in the statistician after the experiment is done may be no > more > than asking him to perform a post-mortem examination: he may be able > to > say what the experiment died of. > ~ Sir Ronald Aylmer Fisher > > The plural of anecdote is not data. > ~ Roger Brinner > > The combination of some data and an aching desire for an answer does > not > ensure that a reasonable answer can be extracted from a given body of > data. > ~ John Tukey > > -----Oorspronkelijk bericht----- > Van: r-help-boun...@r-project.org [mailto:r-help-boun...@r- > project.org] > Namens Hongwei Dong > Verzonden: maandag 3 augustus 2009 19:45 > Aan: r-help@r-project.org > Onderwerp: Re: [R] lme funcion in R > > Thanks for the replies above. Here are my script and data structure: > library(nlme) > tlevel<-lme(fixed = LN_unitlandval ~ > MH_D+APT_D+ResOth_D+NonRes_D+Vacant_D+access_emp1+pct_vacant > +transit_D+p > ark_dum,data=lusdrdata,random > = ~MH_D+APT_D+ResOth_D+NonRes_D+Vacant_D | TAZ) > > str: > > $ TAZ : int 100 100 100 100 100 100 100 100 100 100 ... > $ MH_D : num 0 0 0 0 0 0 0 0 0 0 ... > $ APT_D : num 0 0 0 0 0 0 0 0 0 0 ... $ ResOth_D : num 0 0 0 0 0 0 0 > 0 0 > 0 ... $ NonRes_D : num 0 0 0 0 0 0 0 0 0 1 ... > $ Vacant_D : num 1 1 1 0 0 1 1 1 1 0 ... > $ access_emp1 : num 45.8 45.8 45.8 45.8 45.8 ... > $ pct_vacant : num 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 ... $ > transit_D : > num 0 0 0 0 0 0 0 0 0 0 ... $ park_dum : num 0 0 0 0 0 0 0 0 0 0 ... > > > Thanks. > > Harry > > > > On Mon, Aug 3, 2009 at 10:36 AM, Jason Morgan <jwm-r-h...@skepsi.net> > wrote: > > On 2009.08.03 10:15:46, Hongwei Dong wrote: > Hi, R users, > I'm using the "lme" function in R to estimate a 2 level mixed > effects model, in which the size of the subject groups are > different. It turned > out > that It takes forever for R to converge. I also tried the same thing > > in > SPSS > and SPSS can give the results out within 20 minutes. Anyone can give > > me > some > advice on the lme function in R, especially why R does not converge? > Thanks. > > Harry > > Hello Harry, > > As Chuck mentions, providing some more information on the model and > the data you are using would be helpful. Also, be sure to compare the > optimization methods used in SPSS to that used in R. You can change > the optimization method in R if the default seems to be causing > issues. See help(lmeControl) for numerous setting options. > > ~Jason > > -- > Jason W. Morgan > Graduate Student > Department of Political Science > *The Ohio State University* > 154 North Oval Mall > Columbus, Ohio 43210 > > > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. > > Dit bericht en eventuele bijlagen geven enkel de visie van de > schrijver > weer > en binden het INBO onder geen enkel beding, zolang dit bericht niet > bevestigd is > door een geldig ondertekend document. The views expressed in this > message > and any annex are purely those of the writer and may not be regarded > as > stating > an official position of INBO, as long as the message is not > confirmed by a > duly > signed document. > > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. > > David Winsemius, MD > Heritage Laboratories > West Hartford, CT > > David Winsemius, MD Heritage Laboratories West Hartford, CT [[alternative HTML version deleted]] ______________________________________________ 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.
