try this: > b <- c(1, 0, 1, 0, 1, 0, 1, 0, 1, 0) > p <- c(1, 3, 5, 7) > b[p] <- ifelse(b[p] == 0, 1, 0) > b [1] 0 0 0 0 0 0 0 0 1 0
On Sun, Apr 19, 2009 at 3:24 PM, Esmail <esmail...@gmail.com> wrote: > I have a string of binary values, and I would like to flip certain > bits in a set of positions. > > Let's say the > > vector p contains position [1, 3, 5, 7] > vector b contains bits [1, 0, 1, 0, 1, 0, 1, 0, 1, 0] > result r should be [0, 1, 0, 0, 0, 0, 0, 0, 1, 0] > > in pseudo code this would be something like > > --- > > r = c() > > for (i in 1:10) > if (i in p) > r = c(r, flip[i]) > > r > ---- > > doesn't work :-) R doesn't like the if statement. > > Is there a nice, concise way to do this? The vector contents and > size will vary, but length of p <= b. > > Thanks, > Esmail > > ______________________________________________ > 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. > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve? ______________________________________________ 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.
