On Mon, 31 Oct 2016, Jeff Newmiller wrote:
The help page describes the first argument x as a numeric... it is not designed to accept character,
Actually it is so designed, but not advertised as such. See below.
so the fact that you get anything even close to right is just a bonus. As the doctor says, "if it hurts, don't do that". ave( rep( 1, length( v ), v, FUN=seq_along ) --
[snip]Reading the code of `ave` and then `split<-.default`, you will see subset replacement, "x[i]<- ...", on the argument 'x'. So, the issue is having FUN and that replacement (and possible coercion) yield something useful/sensible. In other words, class(x) need not be "numeric".
For instance, operating on "Date" objects:
# start at 2016-01-02, step 10 days, ...
x <- as.Date("2016-01-01")+seq(1,1000,by=10)
z <- rep(1:10, 10)
class(ave(x,z)) # Date class is preserved
[1] "Date"
[1] "2017-03-27" "2017-04-06" "2017-04-16" "2017-04-26" ...ave(x,z) # mean date
ave(x,z,FUN=min) # earliest date
[1] "2016-01-02" "2016-01-12" "2016-01-22" "2016-02-01" ...However, trying to describe this feature in the help page without a lot of detail and examples might confuse more users than it would enlighten.
-- Chuck ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
