You've tried: diff(c(0, x)) ?
On Wed, Jul 28, 2010 at 3:10 PM, Raghu <r.raghura...@gmail.com> wrote: > Hi > > I have say a large vector of 3500 digits. Initially the digits are 0s and > 1s. I need to check for a rule to change some of the 0s to -1s in this > vector. But once I change a 0 to -1 then I need to start applying the rule > to change the next 0 only after I see the next 1 in the vector. > > Say for example x = (0,0,0,0,0,0,0,1,0,0,1,1,0,0,1,0,0,0,1) > I need to traverse from the 9th element to the last ( because the first > occurrence of 1 is at 8) . Let us assume that according to our rule we > change the 13th element (only 0s can be changed) to -1. Now we need to go > to > the next occurrence of 1 (which is 15) and begin the rule application from > the 16th till the end of the vector and once replaced a 0 to a -1 then > start > again from the next 1. How do we code this? I 'feel' recursion is the best > possible solution but I am not a programmer and will await experts' views. > If this is not a typical R-forum question then my advance apologies. > > Many thx > -- > 'Raghu' > > [[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. > -- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40" S 49° 16' 22" O [[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.
