If I understand you correctly you could just do ifelse(fpr.floor < fpr.ceiling, k.floor, k.ceiling)
cheers, Rolf Turner [EMAIL PROTECTED] ===+===+===+===+===+===+===+===+===+===+===+===+===+===+===+===+===+===+=== Seung Jun wrote: > I have two vectors (k.floor and k.ceiling) of integers of the same > length, and a function (fpr). > > b <- 10:40 > k.floor <- floor(log(2) * b) > k.ceiling <- ceiling(log(2) * b) > fpr.floor <- fpr(b, k.floor) > fpr.ceiling <- fpr(b, k.ceiling) > > If R had a element-wise ternary function, I'd like to do something like > this: > > (fpr.floor < fpr.ceiling) ? k.floor : k.ceiling > > That is, I'd like to go through the two vectors in parallel, picking > the one that returns the lower value of fpr. Failing to find such a > function, I wrote the following two lines: > > ind <- sapply(data.frame(rbind(fpr.floor,fpr.ceiling)), which.min) > opt.k <- cbind(k.floor,k.ceiling)[1:length(ind)+length(ind)*(ind-1)] > > opt.k is the vector I want, but I guess I abuse some functions here. > I'd like to ask the experts, What is the proper R-way to do this? > > The API should be like "which.pmin(FUN, X, Y, ...)" that returns a > vector of the same length as X (and Y), provided that X, Y, ... have > the same length. Please fill the function body. ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html