Thanks David, I never thought of using merge for this. I usually used the "cast" command from the "reshape" package for this type of task.
Cheers, Tal ----------------Contact Details:------------------------------------------------------- Contact me: tal.gal...@gmail.com | 972-52-7275845 Read me: www.talgalili.com (Hebrew) | www.biostatistics.co.il (Hebrew) | www.r-statistics.com (English) ---------------------------------------------------------------------------------------------- On Fri, Apr 2, 2010 at 11:31 PM, David Winsemius <dwinsem...@comcast.net>wrote: > > On Apr 2, 2010, at 3:39 PM, Geoffrey Smith wrote: > > Hello, I have an unbalanced panel data set that looks like: >> >> ID,YEAR,HEIGHT >> Tom,2007,65 >> Tom,2008,66 >> Mary,2007,45 >> Mary,2008,50 >> Harry,2007,62 >> Harry,2008,62 >> James,2007,68 >> Jack,2007,70 >> Jordan,2008,72 >> >> That is, James, Jack, and Jordan are missing a YEAR. >> >> Is there any command that will "fill in" the missing YEAR such that the >> end >> result will be balanced and look like: >> >> ID,YEAR,HEIGHT >> Tom,2007,65 >> Tom,2008,66 >> Mary,2007,45 >> Mary,2008,50 >> Harry,2007,62 >> Harry,2008,62 >> James,2007,68 >> James,2008,NA >> Jack,2007,70 >> Jack,2008,NA >> Jordan,2007,NA >> Jordan,2008,72 >> > > It's not "one command" but it's an approach ... assumes you have data in a > dataframe named ftbl: > > > fexp <- expand.grid(ID=unique(ftbl$ID), YEAR=unique(ftbl$YEAR)) > > merge(fexp, ftbl, all=TRUE) > > ID YEAR HEIGHT > 1 Harry 2007 62 > 2 Harry 2008 62 > 3 Jack 2007 70 > 4 Jack 2008 NA > 5 James 2007 68 > 6 James 2008 NA > 7 Jordan 2007 NA > 8 Jordan 2008 72 > 9 Mary 2007 45 > 10 Mary 2008 50 > 11 Tom 2007 65 > 12 Tom 2008 66 > > > > -- > > David Winsemius, MD > West Hartford, CT > > > ______________________________________________ > 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. > [[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.
