On Tue, 9 Dec 2003, David Kreil wrote:
>
> Hi,
>
> I have a data.frame that I need to construct iteratively.
>
> At the moment, I'm doing:
>
> d<-data.frame(x=c(),y=c(),z=());
>
> # {and, within some loop}
>
> d<-rbind(d,data.frame(x=newx,y=newy,z=newz);
>
>
> While this works, it is horribly verbose and probably not efficient, either.
> My real data.frame has, of course, many more columns, which can be of
> different modes.
>
> I vaguely recall that in much earlier R versions the following worked
>
> d[dim(d)[1]+1,]<-c(newx,newy,newz);
>
> but not anymore (both 1.7 and 1.8 give "subscript out of bounds").
>
> Can anyone suggest a more elegant and/or efficient way of achieving this,
> please? Cc to this address highly appreciated.
Just allocate a large enough data frame to start with, then use indexing
to insert the rows. If you cannot get a good bound on the eventual size,
over-allocate and double in size as needed.
--
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
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