my specific question is: I am attempting to create a bootstrap procedure for a finite sample using the theory of Rao and Wu, JASA (1988) that replicates within each strata (h) n_h - 1 times. I am able to sample n_h times using an innitial call to the resample function I suspect that it has to do with providing extra info to the FUN function but this seems to only allow one value i.e tapply(test, class, mean, trim = 0.1) i want to be able to have a different value of n for each sampler <- function(x) { sample(x, replace = T) } raoboot <- function (datavar, statavar, weight, nboot) { i <- 1 sdatavar <- sort(datavar) sstratavar <- sort(statavar) sweight <- sort(weight) sdatavarwght <- sdatavar*sweight stramn <- tapply(sdatavar, sstratavar, mean) meanvect <- rep(0, times = nboot) while (i < nboot) { #vector of resampled observations vectobsrestemp <- tapply(sdatavarwght, sstratavar, resampler) vectobsres <- unlist(vectobsrestemp) meanvect[i] <- mean(vectobsres) i <- i + 1 } repvectboot <- rep(mean(meanvect), times = i) vb <- sum((repvectboot - meanvect)^2)/(i -1) }