On May 10, 2014, at 3:54 AM, Duncan Murdoch wrote: > On 10/05/2014, 6:46 AM, Barry Rowlingson wrote: >> On Fri, May 9, 2014 at 10:42 PM, Hadley Wickham <h.wick...@gmail.com> wrote: >>> Beware of the is.* functions: >>> >>> * is.object() does not test the usual definition of objects >>> * is.vector() does not test the usual definition of vectors >>> * is.numeric() does not work the same way as is.character() or is.integer() >>> * is.Date() doesn't exist >>> * is.nan() doesn't return TRUE for some NaNs >> >> Can we have an "is.is" function that tells us these things? >> >> > is.is(is.object) >> [1] FALSE >> Warning: is.object() does not test the usual definition of objects >> >> > is.is(is.is) >> [1] TRUE >> >> For further exploration, demo("is.things") creates a handy "is.ALL" >> function that outputs the result of running a lot of is.X functions on >> its argument. > > I tried to write it, but the trouble is, is.is(is.is) is FALSE.
Perhaps the R engine will surmount the Singularity when `is.think` returns `is.is`. > > Duncan > David Winsemius Alameda, CA, USA ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.