[R] getting data frame rows out of a by object
Ed L Cashin
ecashin at uga.edu
Thu Apr 8 16:22:21 CEST 2004
Douglas Bates <bates at stat.wisc.edu> writes:
> The point is that factor(paste(...)) returns a factor with length of
> nrow(d) and with factor levels determined by the combination of levels
> of a and b (provided that you don't get ambiguities as described
> above). The split function does not require that the factor
> determining the splits be part of the data frame being split. It can
> be given explicitly as it is here.
I think I need to look at the source of split when I have more time.
>  If you really want to be cautious you could use an octal
> representation like sep="\007" to get a character that is very
> unlikely to occur in a factor level.
I definitely want to be cautious. Instead of the bell character I
think I'll use the field separator character, "\034", just because
this is the first time I've been able to use it for it's intended
--Ed L Cashin | PGP public key:
ecashin at uga.edu | http://noserose.net/e/pgp/
More information about the R-help