[Rd] A couple of issues with colClasses/setAs
Prof Brian Ripley
ripley at stats.ox.ac.uk
Wed Sep 8 20:19:57 CEST 2004
On 8 Sep 2004, Peter Dalgaard wrote:
> Prof Brian Ripley <ripley at stats.ox.ac.uk> writes:
> > > etc? Or perhaps it is better with a catchall "Date-fmt", i.e., e.g.,
> > > "Date-%Y%m%d"? That'd be fairly easy to code:
> > >
> > > else if (length(grep("^Date-",colClasses[i])))
> > > as.Date(data[[i]], sub("^Date-(.*)$","\\1", colClasses[i]))
> > >
> > > although perhaps not so easy to document concisely.
> > Is it really so hard to convert such columns from character afterwards?
> Couldn't that be said for all of the classes?
Yes, which is why the original colClasses only dealt with those that could
avoid conversion (where there can be large time and space benefits).
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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