Like this? d = read.table(textConnection("ID PM adt_01 25.255 adt_01 225.36 adt_01 14.2325 adt_02 15 adt_02 12.3 adt_03 15.2 adt_03 148.3 adt_03 25.5 adt_03 14.25"),head=T) d d$PM <- as.numeric(d$PM) ddply(d,.(ID),numcolwise(median))
Felipe D. Carrillo Supervisory Fishery Biologist Department of the Interior US Fish & Wildlife Service California, USA --- On Wed, 1/27/10, "María del Pilar Márquez" <marquezvi...@wisc.edu> wrote: > From: "María del Pilar Márquez" <marquezvi...@wisc.edu> > Subject: [R] median of grouped data > To: r-help@r-project.org > Date: Wednesday, January 27, 2010, 10:05 AM > Good morning, > I would like to know if is possible somebody can help me > with this please: > I would like to calculate the median of grouped data, this > is an example: > > ID PM > adt_01 25.255 > adt_01 225.36 > adt_01 14.2325 > adt_02 15 > adt_02 12.3 > adt_03 15.2 > adt_03 148.3 > adt_03 25.5 > adt_03 14.25 > > I need the median of adt_01, 02 and 03 , I know that I have > to split first my data and then ask for the median but the > code I have is not working. > > Thank you very much if you can help me with the code > maria > > ______________________________________________ > 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. > ______________________________________________ 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.