On 11/9/05, Todd A. Gibson <[EMAIL PROTECTED]> wrote: > On Tue, Nov 08, 2005 at 10:47:26PM -0500, Gabor Grothendieck wrote: > > Also, one can use aggregate: > > > > aggregate(DF[,-1], list(month = DF$month), max) > > The issue here is that I need the row corresponding to the month with > the maximum length. That is, aggregate(.) is returning both the > maximum month and maximum ratio for all rows with month=Jan. I need > the single row in month=Jan which has the maximum length.
Try this to calculate the index, idx, of the largest in each group and then put it all together in the last line: f <- function(x) rownames(x)[which.max(x$length)] idx <- by(DF, DF$month, f) cbind(index = c(idx), DF[idx,]) ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
