One option is use this: aggregate(list(t=tt$t), list(idx=tt$idx), length)
On Thu, Aug 28, 2008 at 4:36 PM, <[EMAIL PROTECTED]> wrote: > Folks, > > I've been running into an odd situation that occurs when I use length() > function with aggregate(), but not with either one separately. Together, > the results looks correct but is given an unexpected name. 'if > (stringsAsFactors) factor(x) else x' instead of just 'x'. > > # Numbers work ok > tt <- data.frame(idx=c(1,1,1,1,1,1,2,2,2,2,2,2) > ,n=c(1,3,5,7,5,5,2,4,8,16,4,4) > ,t=c(1,3,5,7,5,5,2,4,8,16,4,4) > ,stringsAsFactors=FALSE) > > aggregate(tt$t, list('idx'=tt$idx), length) > aggregate(as.factor(tt$t), list('idx'=tt$idx), length) > > # Character data doesn't work right unless I convert the data to factors. > tt <- data.frame(idx=c(1,1,1,1,1,1,2,2,2,2,2,2) > ,n=c('1','3','5','7','5','5','2','4','8','16','4','4') > ,t=c('1','3','5','7','5','5','2','4','8','16','4','4') > ,stringsAsFactors=FALSE) > > aggregate(tt$t, list('idx'=tt$idx), length) > aggregate(as.factor(tt$t), list('idx'=tt$idx), length) > > > Any idea what is going on here? For the record, this also happens with > the modalvalue() function defined at > http://wiki.r-project.org/rwiki/doku.php?id=tips:stats-basic:modalvalue > (which also relies on length() ). > > As a side note, this began as an attempt to determine sample size, for > which I've defined a function count <- function(x) { length(na.omit(x)) }. > No doubt there's a built in function to do just that, but as a newbie > I've yet to find it. > > Thank you for your help, > cur > -- > Curt Seeliger, Data Ranger > Raytheon Information Services - Contractor to ORD > [EMAIL PROTECTED] > 541/754-4638 > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > 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. > -- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40" S 49° 16' 22" O [[alternative HTML version deleted]]
______________________________________________ R-help@r-project.org mailing list 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.