Hi I am not sure if I understand your function but simple mapply gives you probably the same result and may be quicker.
> set.seed(111) > blf <- bl_func() > set.seed(111) > blm <- mapply(sample, bl, kn, replace=TRUE) > all.equal(blf, blm) [1] TRUE > Cheers Petr > -----Original Message----- > From: R-help <[email protected]> On Behalf Of Chao Liu > Sent: Tuesday, February 2, 2021 3:32 PM > To: r-help <[email protected]> > Subject: [R] Alternative to mapply to select samples > > Dear R-Help, > > I created a mapply function to select samples from a dataset but are there > any faster ways to do it by avoiding mapply because it is slow and I have a > larger dataset? My goal is to use more matrix / vector operations and less > in terms of lists (the format of the output can be flexible). Ideally, I > would like to stick to base R methods without the aid of parallel process > or packages. Any ideas will be appreciated! > > #A list of a set of data to be selected > bl <- list(list(c(1, 2),c(2, 3), c(3, 4), c(4, 5), c(5, 6), c(6, 7), c(7, > 8), c(8, 9)), > list(c(1, 2, 3), c(2, 3, 4), c(3, 4, 5), c(4, 5, 6), c(5, 6, 7), > c(6, 7, 8)), > list(c(1, 2, 3, 4, 5), c(2, 3, 4, 5, 6), c(3, 4, 5, 6, 7), c(4, 5, > 6, 7, 8), c(5, 6, 7, 8, 9))) > #Number of elements to be selected > kn <- c(5, 4, 3) > #Total number of elements in each set > nb <- c(8, 6, 5) > #This output a list but preferably I would like a matrix > bl_func <- function() mapply(function(x, y, z) { > x[sample.int(y, z, replace = TRUE)] > }, bl, nb, kn, SIMPLIFY = FALSE) > > Best, > > Chao > ᐧ > > [[alternative HTML version deleted]] > > ______________________________________________ > [email protected] mailing list -- To UNSUBSCRIBE and more, see > 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.
______________________________________________ [email protected] mailing list -- To UNSUBSCRIBE and more, see 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.
