On Tue, 14 Nov 2006, Weiwei Shi wrote:
> Hi,
> I am writing a generic function and need to check if an arg is a data
> frame or not.
?is.data.frame
> I could use is.null(dim(x)) to get what i want.
In which case you would fail. Arrays and many other objects have non-NULL
dims.
> But i want to know if there is a
> function which can tell me whether it is a list, a numeric vector, a
> data frame, a factor and so on. Can R do that?
Yes. ?typeof, ?class, ?str, ?inherits ... and please do study 'An
Introduction to R' (belatedly).
You do seem to be asking almost daily for people to read the documentation
for you. Please try
install.packages("fortunes"); library(fortunes); fortune("WTFM")
--
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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