[R] extract numerical variables from a data frame
Prof Brian Ripley
ripley at stats.ox.ac.uk
Fri Aug 29 11:21:43 CEST 2003
On Fri, 29 Aug 2003, Vincent Spiesser wrote:
> I try to create from a data frame a new one which contains only the
> numerical variables (or factorial ones).
> Is there any function which does this task directly ?
> Or, is there any function which return the mode of each columns of a data
> frame. ?
I think you want the class, as in
You could use mode if you really wanted it, but watch out for e.g. the
mode of a factor being "numeric".
However, for your original question I would use
and similar code is found throughout the R sources.
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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