On 17-Jun-2012 17:24:21 ÀîºìÍú wrote: >> a<-c(1,4) >> a > [1] 1 4 >> b<-a*5 >> b > [1] 5 20 > > a is a very long vector , how can i get c(1:5,4:20)? > i do not want to use a loop. > > thanks very much!
Your question is not quite clear, but I think you mean: a is a very long vector, and you want a vector with elements a[1],a[2],a[3],a[4],a[5],a[4],a[5],a[6],...,a[20] If that is the case, then a[c(1:5,4:20)] will do it. Example: a <- (1:100) a[c(1:5,4:20)] # [1] 1 2 3 4 5 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Does that help? If not, try to re-formulate the question! Ted. ------------------------------------------------- E-Mail: (Ted Harding) <ted.hard...@wlandres.net> Date: 17-Jun-2012 Time: 20:58:01 This message was sent by XFMail ______________________________________________ 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.
