Re: [Rd] string-length limitations

From: jake wilson <jake_f_wilson_at_hotmail.com>
Date: Wed 12 Jul 2006 - 18:10:48 GMT


Thank you - the proposed solution (eliminating quotes) worked.

>From: Prof Brian Ripley <ripley@stats.ox.ac.uk>
>To: jake wilson <jake_f_wilson@hotmail.com>
>CC: r-devel@r-project.org
>Subject: Re: [Rd] string-length limitations
>Date: Wed, 12 Jul 2006 15:38:22 +0100 (BST)
>
>On Wed, 12 Jul 2006, jake wilson wrote:
>
> > Hi,
> >
> > I'm attempting to "glm" a formula - something that's not caused problems
>in
> > the past. I've used formulas of the form
> >
> > formula( "dependant-variable~independant-variables" )
> >
> > where the independant variable string is of the form:
> >
> > "indvar1+indvar2+...+indvarN"
>
>Why the quotes?: I think that is your problem.
>
> > Now, however, our independant variable strings are quite long (hundreds
>of
> > variables) - R dies with an "input buffer overflow" error.
>
>It is normal to use (y ~ ., data=mydata) to avoid such formulae.
>
> > I've tried writing out the code to files and sourcing them, as well as
> > building the strings incrementally in R, but these have not worked
> > either. I have come to believe there is a maximum length for char
> > strings - some sort of fundamental limitation. Is there such a
> > max-length and, if so, is there a way I can work with long strings of
> > the sort referenced above?
>
>The limit is 2^31 -1, not relevant here.
>
>Your message is coming from the parser, and suggests that it is trying to
>parse a piece of text longer than MAXELTSIZE bytes. The latter depends on
>the platform (unstated: do see the posting guide) and is often 8196 bytes.
>So there is a limit on the length of quoted strings which can be input.
>
>However, what is wrong with say
>
>tmp <- paste(paste("indvar", 1:1000, sep=""), collapse="+")
>tmp <- paste("y ~", tmp)
>form <- eval(parse(text=tmp))
>
>?
>
>--
>Brian D. Ripley, ripley@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



R-devel@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-devel Received on Thu Jul 13 04:16:47 2006

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.1.8, at Thu 13 Jul 2006 - 04:23:54 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.