Hi, On Tue, Jan 10, 2012 at 6:04 PM, Eric Rupley <erup...@umich.edu> wrote: > > Hi-- > > I suspect this is a frequently considered (and possibly asked) question, but > I haven't thus far found an answer: > > For slicing a vector with x[…], is there a symbol for length(x)? > > I'm seeking a short-hand for referring to the length of vector one is trying > to index. > > E.g., for a data.frame, say, > >> test.frame <-data.frame(matrix(c(1:100),ncol=10,nrow=10,byrow=T)) >> names(test.frame) <- names(islands)[1:10] > > is there a short-hand for subsetting > >> test.frame$Baffin[1:(length(test.frame$Baffin)-3)] > [1] 6 16 26 36 46 56 66 >> >> > > that would allow one to avoid the "(length(some.dataframe$variable)-offset)"?
Sadly there is no shorthand of the (exact) type you are looking for. You can access the data like so, however: R> head(test.frame$Baffin, -3) [1] 6 16 26 36 46 56 66 I think that's as good as you're going to get, but let's see what other suggestions pop up. -steve -- Steve Lianoglou Graduate Student: Computational Systems Biology | Memorial Sloan-Kettering Cancer Center | Weill Medical College of Cornell University Contact Info: http://cbio.mskcc.org/~lianos/contact ______________________________________________ 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.
