You can do this too: aggregate(iris[-5], iris["Species"], mean)
or this: with(iris, aggregate(iris[-5], data.frame(Species), mean)) or this: attach(iris) aggregate(iris[-5], data.frame(Species), mean) The point is that you already don't have to write x = x. The only reason you are writing it that way is that you are using list instead of data.frame. Just use data.frame or appropriate indexing as shown. On 9/27/07, Mike Lawrence <[EMAIL PROTECTED]> wrote: > Understood, but my point is that the naming I suggest should be the > default. One should not be 'punished' for being explicit in calling > aggregate. > > > On 27-Sep-07, at 1:06 PM, Gabor Grothendieck wrote: > > > You can do this: > > > > aggregate(iris[-5], iris[5], mean) > > > > > > On 9/27/07, Mike Lawrence <[EMAIL PROTECTED]> wrote: > >> Hi all, > >> > >> A suggestion derived from discussions amongst a number of R users in > >> my research group: set the default column names produced by aggregate > >> () equal to the names of the objects in the list passed to the 'by' > >> object. > >> > >> ex. it is annoying to type > >> > >> with( > >> my.data > >> ,aggregate( > >> my.dv > >> ,list( > >> one.iv = one.iv > >> ,another.iv = another.iv > >> ,yet.another.iv = yet.another.iv > >> ) > >> ,some.function > >> ) > >> ) > >> > >> to yield a data frame with names = c > >> ('one.iv','another.iv','yet.another.iv','x') when this seems more > >> economical: > >> > >> with( > >> my.data > >> ,aggregate( > >> my.dv > >> ,list( > >> one.iv > >> ,another.iv > >> ,yet.another.iv > >> ) > >> ,some.function > >> ) > >> ) > >> > >> -- > >> Mike Lawrence > >> Graduate Student, Department of Psychology, Dalhousie University > >> > >> Website: http://memetic.ca > >> > >> Public calendar: http://icalx.com/public/informavore/Public > >> > >> "The road to wisdom? Well, it's plain and simple to express: > >> Err and err and err again, but less and less and less." > >> - Piet Hein > >> > >> ______________________________________________ > >> R-devel@r-project.org mailing list > >> https://stat.ethz.ch/mailman/listinfo/r-devel > >> > > -- > Mike Lawrence > Graduate Student, Department of Psychology, Dalhousie University > > Website: http://memetic.ca > > Public calendar: http://icalx.com/public/informavore/Public > > "The road to wisdom? Well, it's plain and simple to express: > Err and err and err again, but less and less and less." > - Piet Hein > > > ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel