For future reference you may want to look at the plyr package, or even the sapply and aggregate functions and possibly simpler ways to do what you did below.
-- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare greg.s...@imail.org 801.408.8111 > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r- > project.org] On Behalf Of Nick Ackerman > Sent: Wednesday, March 17, 2010 11:45 AM > To: r-help@r-project.org > Subject: Re: [R] How can I return rows from a data frame with maximum > value by factor? > > > Solved my own question by looking at some other threads. For those who > may be > intersted, here was the solution to my problem. > > do.call(rbind,lapply(split(data.frame,FISH_ID),function(x)x[which.max(x > $DATE_TIME),])) > -- > View this message in context: http://n4.nabble.com/How-can-I-return- > rows-from-a-data-frame-with-maximum-value-by-factor- > tp1596777p1596853.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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.
