[R] Idioms for empty dataframes
ranjan.bagchi at frotz.com
Mon Oct 1 18:01:13 CEST 2007
I'm fairly new to R, coming from a programming background -- it's quite
nice to work with dataframes, though, as opposed to explicit iteration.
One thing I've found, which is surprising is that zero-length dataframes
seem to cause errors:
> t <- data.frame(bob=c(100))
> t1 <- t[t$bob < 50]
Error in order(na.last, decreasing, ...) :
argument 1 is not a vector
I'd expect c() as a result, not an error.
So I have two questions --
Is there something important I'm misunderstanding?
What idioms do experts use to deal with this? Just calling nrow to
handle the 0 case? Something cleaner?
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