On Jun 28, 2013, at 23:58 , Julio Sergio wrote: > One of the techniques to subset, a vector for instance, is the following: > > V <- c(18, 8, 5, 41, 8, 7) > V > ## [1] 18 8 5 41 8 7 > ( I <- abs(V - 9) <= 3 ) > ## [1] FALSE TRUE FALSE FALSE TRUE TRUE > V[I] > ## [1] 8 8 7 > > However, sometimes we are interested in the indexes of the elements where the > condition holds. Is there an easy way to transform the I vector into an > indexes vector similar to: I == c(2,5,6) ? > > I know that I can traverse the I vector with a for() loop collecting the > indexes, I just wonder if such an operation can be avoided. >
which(I) -- Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Email: pd....@cbs.dk Priv: pda...@gmail.com ______________________________________________ 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.