On 4/25/2010 2:10 PM, Alan Lue wrote: > Hi, > > Is there a way to specify the last element of a vector, similar to "end" in > MATLAB? > > v[end] > > would be MATLAB for > > v(length(v)) > > in R. > > While `v(length(v))' does yield the last element, that approach fails in the > following, > > rep(v, each=2)[-c(1,length(v))] > > which is meant to duplicate all elements of `v' except for the first and > last. (I.e., if `v <- 1:4', then we want '1 2 2 3 3 4'.)
v <- 1:4 rep(v, c(1, rep(2, length(v) - 2), 1)) [1] 1 2 2 3 3 4 > So the question is, is there a better way specify the last element of a > vector? If not, is there a better way to duplicate all elements of a vector > except for the first and last? (I know you can achieve this using two > lines, but I'm writing because I want to do it using one.) > > Alan -- Chuck Cleland, Ph.D. NDRI, Inc. (www.ndri.org) 71 West 23rd Street, 8th floor New York, NY 10010 tel: (212) 845-4495 (Tu, Th) tel: (732) 512-0171 (M, W, F) fax: (917) 438-0894 ______________________________________________ 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.
