On 12/02/2011 07:20 AM, Aurélien PHILIPPOT wrote: > Dear R-users, > -I am new to R, and I am struggling with the following problem. > > -I am repeating the following operations hundreds of times, within a loop: > I want to subset a data frame by columns. I am interested in the columns > names that are given by the rows of another data frame that was built in > parallel. The solution I have so far works well as long as the elements of > the second data frame are included in the column names of the first data > frame but if an element from the second object is not a column name of the > first one, then it bugs.
Hi Aurelien, I would call this a feature, not a bug. I think R does what it should do, you request a non-existent column and it throws an error. What kind of behavior are you looking for instead of this error? regards, Paul > > -More concretely, I have the following data frames d and v: > yyyymmdd<-c("19720601", "19720602", "19720605") > sret.10006<-c(1,2,3) > sret.10014<-c(5,9,7) > sret.10065<-c(10,2,11) > > > d<- data.frame(yyyymmdd=yyyymmdd, sret.10006=sret.10006, > sret.10014=sret.10014, sret.10065=sret.10065) > > v<- data.frame(V1="sret.10006", V2="sret.10090") > v<- sapply(v, function(x) levels(x)[x]) > > -I want to do the following subsetting: > sub<- subset(d, select=c(v)) > > > and I get the following error message: > Error in `[.data.frame`(x, r, vars, drop = drop) : > undefined columns selected > > > > Any help would be very much appreciated, > > Best, > Aurelien > > [[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. -- Paul Hiemstra, Ph.D. Global Climate Division Royal Netherlands Meteorological Institute (KNMI) Wilhelminalaan 10 | 3732 GK | De Bilt | Kamer B 3.39 P.O. Box 201 | 3730 AE | De Bilt tel: +31 30 2206 494 http://intamap.geo.uu.nl/~paul http://nl.linkedin.com/pub/paul-hiemstra/20/30b/770 ______________________________________________ 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.