Expectation: ifelse will use the same "repeat vectors to match the longest" rule that other vectorised functions do. So a <- 1:5 b <- c(2,3) ifelse(a < 3, 1, b) => ifelse(T T F F F <<5>>, 1 <<1>>, 2 3 <<2>>) => ifelse(T T F F F <<5>>, 1 1 1 1 1 <<5>>, 2 3 2 3 2 <<5>>) => 1 1 2 3 2 and that is indeed the answer you get. Entirely predictable and consistent with other basic operations in R.
The only tricky thing I see is that R has a strict vectorised ifelse(logical.vector, some.vector, another.vector) AND a non-strict non-vectorised if (logical.scalar) some.value else another.value AND a statement form if (logical.scalar) stmt.1; else stmt.2; On Thu, 11 Jul 2019 at 01:47, Eric Berger <ericjber...@gmail.com> wrote: > For example, can you predict what the following code will do? > > a <- 1:5 > > b <- c(2,3) > > ifelse( a < 3, 1, b) > > > On Wed, Jul 10, 2019 at 4:34 PM José María Mateos <ch...@rinzewind.org> > wrote: > > > On Wed, Jul 10, 2019, at 04:39, Eric Berger wrote: > > > 1. The ifelse() command is a bit tricky in R. Avoiding it is often a > good > > > policy. > > > > You piqued my curiosity, can you elaborate a bit more on this? > > > > -- > > José María (Chema) Mateos || https://rinzewind.org > > > > ______________________________________________ > > R-help@r-project.org 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. > > > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org 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. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org 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.
