try something like: r$deltact[r$time == '0h'] <- 0
On Sat, May 29, 2010 at 7:50 PM, ANJAN PURKAYASTHA <anjan.purkayas...@gmail.com> wrote: > Hi, > I have a data-frame r (shown below is a subset) with the following column > names: > date time sample vct norm hct deltact > > $time has 8 levels: 0h, 0.5h, .....24h. $deltact holds real numbers. > I want to subset this dataframe by the levels of $time. For all the rows > which have r$time == "0h" I would like to convert the present value of > r$deltact to 0. > Any pointers to a simple method to accomplish would be greatly appreciated. > > TIA, > Anjan > > > -- > =================================== > anjan purkayastha, phd. > research associate > fas center for systems biology, > harvard university > 52 oxford street > cambridge ma > phone-703.740.6939 > =================================== > > [[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. > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve? ______________________________________________ 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.
