Does it make any statistical sense to do polr or probit regression (not the same thing) on `really huge data'? There are few regression-like problems in which model inadequacy does not swamp estimation uncertainty for as few as a 1000 cases.
If you want to do that sort of thing, by all means use SAS to do it. But if you are not prepared to spend a few $$ on adequate RAM, don't expect free technical consultancy, especially not from those whose work you are using and not crediting. - The uncredited author of polr(). On Mon, 14 Aug 2006, T Mu wrote: > Hi all, > > I was trying a probit regression using polr() and got this message, polr is a strange choice of tool for 'probit regression' as the term is usually used. It does 'ordered probit regression'. > Error in model.matrix.default(Terms, m, contrasts) : > cannot allocate vector of length 828310236 > > The data is about 20M (a few days ago I asked a question about large file, > thank you for responses, then I use MS Access to select those columns I > would use). > > R is 2.3.1, Windows XP, 512M Ram. > > I am going to read some help on memory use in R, but hope anybody can give > me some quick hints. Quick hint: read and follow the posting guide BEFORE posting. > Is it because iphysical memory runs out, or some other things could be wrong > with data or polr()? > Does R use virtual memory? If so, what options can I set? > If not, can R deal with really huge data (except adding RAM according to > data size)? If this is the case, it is too bad that I have to tell my boss > to go back to SAS. Now it is not a speed issue yet. > > Thank you. > > [[alternative HTML version deleted]] > > ______________________________________________ > [email protected] 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. > -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ [email protected] 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.
