john james
2008-Jul-25 19:31 UTC
[R] Selecting the first measurement only from a longitudinal sequence
Dear R-help mailing list, I have this problem, I have a joint longitudinal and survival data of the form say ID Time Failuretime Censoringind longitudinalmeasure 1 0 35 0 123 1 10 35 0 120 1 25 35 1 123 2 0 23 0 100 2 10 23 0 111 I wish to create a new dataset such that only the first measurement is included. Also, i will appreciate if there is a function that i could call to do this because I will be applying it too in a simulation settings. Thank you for your time. James. [[alternative HTML version deleted]]
jim holtman
2008-Jul-26 03:09 UTC
[R] Selecting the first measurement only from a longitudinal sequence
Is this what you want:> x <- read.table(textConnection("ID Time Failuretime Censoringind longitudinalmeasure+ 1 0 35 0 123 + 1 10 35 0 120 + 1 25 35 1 123 + 2 0 23 0 100 + 2 10 23 0 111"), header=TRUE)> do.call(rbind, lapply(split(x, x$ID), function(.grp) .grp[1,]))ID Time Failuretime Censoringind longitudinalmeasure 1 1 0 35 0 123 2 2 0 23 0 100> > >On Fri, Jul 25, 2008 at 3:31 PM, john james <dntssa at yahoo.com> wrote:> Dear R-help mailing list, > > I have this problem, I have a joint longitudinal and survival data of the form say > > ID Time Failuretime Censoringind longitudinalmeasure > 1 0 35 0 123 > 1 10 35 0 120 > 1 25 35 1 123 > 2 0 23 0 100 > 2 10 23 0 111 > > > I wish to create a new dataset such that only the first measurement is included. > > Also, i will appreciate if there is a function that i could call to do this because I will be applying it too in a simulation settings. > > Thank you for your time. > > James. > > > > [[alternative HTML version deleted]] > > > ______________________________________________ > R-help at 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. > >-- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem you are trying to solve?
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