[R] comparing the previous and next entry of a vector to a criterium

Hi, I have a quit abstract problem, hope someone can help me here. I have a vector like this: x - c(1,2,3,4,5,2,6) x [1] 1 2 3 4 5 2 6 now I want to get the number where the previous number is 1 and the next number is 3 (that is the 2 at the second place) I tried something with

Re: [R] comparing the previous and next entry of a vector to a criterium

How about: a - c(1,2,3,3,2,1,6,3,2) b - c(NA,a[-length(a)]) c - c(a[-1],NA) a[b==1 c==3] [1] 2 6 hth, Kingsford Jones On Sun, Jan 25, 2009 at 3:02 PM, Jörg Groß jo...@licht-malerei.de wrote: Hi, I have a quit abstract problem, hope someone can help me here. I have a vector like this: