If DF is your data.frame: subset(cbind(DF, baseline=rep(DF$Y[DF$time == 0], table(DF$ID))), time > 0)
On Tue, Sep 16, 2008 at 11:01 AM, john james <[EMAIL PROTECTED]> wrote: > Dear R-help mailing list, > > Kindly help me out with this problem: > > I have a dataset that is in the format below, > ID time Y Age > 1 0 195 23.1 > 1 2 204 23.3 > 1 4 202 23.5 > 2 0 170 22.0 > 2 3 234 22.2 > 3 0 208 24.4 > 3 2 194 24 .7 > 3 3 204 24.9 > > I wish to remove all the measurements at time point 0 and convert them to a > baseline variable as follows; > > ID time Y Age baseline > 1 2 204 23.3 195 > 1 4 202 23.5 195 > 2 3 234 22.2 170 > 3 2 194 24 .7 208 > 3 3 204 24.9 208 > > Thanks. > > regards > John > > > > > > [[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.
