Hi change max_dt do PISIX class and use standard comparison operator and use the result for selecting rows.
> s<-seq(c(ISOdate(2000,3,20)), by = "day", length.out = 10) > s<s[5] [1] TRUE TRUE TRUE TRUE FALSE FALSE FALSE FALSE FALSE FALSE > Regards Petr > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-bounces@r- > project.org] On Behalf Of ramoss > Sent: Thursday, May 23, 2013 4:24 PM > To: r-help@r-project.org > Subject: [R] Removing rows w/ smaller value from data frame > > Hello, > > I have a column called max_date in my data frame and I only want to > keep the bigger values for the same activity. How can I do that? > > data frame: > > activity max_dt > A 2013-03-05 > B 2013-03-28 > A 2013-03-28 > C 2013-03-28 > B 2013-03-01 > > Thank you for your help > > > > -- > View this message in context: http://r.789695.n4.nabble.com/Removing- > rows-w-smaller-value-from-data-frame-tp4667816.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.
