As others have noted, this is discussed in many free R tutorials, but if you want to do it in one line I think this should do it:
X[is.NA(X[,"b"])&(X[,"c"]==0),"b"]<-"2011-07-28" #where X is the name of the data frame. It's a somewhat convoluted line of code but if you read it inside out the logic is clear: Find those rows where column b is NA and c is 1 by searching all rows of the relevant column (the X[,something] syntax): select those rows and the b column. Put the desired date in those slots. let me know of I can further clarify this. I changed the date assuming a typo on your end. Welcome and good luck getting started with R, Michael Weylandt On Aug 3, 2011, at 4:05 AM, zcatav <zca...@gmail.com> wrote: > Hello, > I have a big data.frame, a piece of it as follows. > > a b c d > 1 58009 2010-11-02 0 NA > 2 114761 NA 1 2008-11-05 > 3 184440 NA 1 2009-12-08 > 4 189372 NA 0 NA > 5 105286 NA 0 NA > 6 186717 NA 0 NA > 7 189106 NA 0 NA > 8 127306 NA 0 NA > 9 157342 2011-04-25 0 NA > > I want to replace b[NA] values with "20011-07-28" where c==0. I use rstudio > and i'm a novice. > > > -- > View this message in context: > http://r.789695.n4.nabble.com/conditional-data-replace-recode-change-or-whatsoever-tp3714715p3714715.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.
