[R] help: cannot allocate vector of length 828310236
Prof Brian Ripley
ripley at stats.ox.ac.uk
Tue Aug 15 08:27:36 CEST 2006
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]]
> R-help at stat.math.ethz.ch mailing list
> 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, ripley at stats.ox.ac.uk
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
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