Hi The function `check_irregular()` defined within `graphics::image.default()` checks if the `useRaster` argument for `graphics::image()` can be true or must be false.
According to this function, the following example vector is irregular: ``` time <- seq(as.Date("2020-1-1"), as.Date("2020-12-31"), l=12) check_irregular(time, time) # TRUE ``` In my view, this is not correct. In this case, the `all.equal`-call does not evaluate to true due to the special class of `dx` (or `dy`). If I slightly rewrite the function as ``` my_check_irregular <- function (x, y) { dx <- as.numeric(diff(x)) dy <- as.numeric(diff(y)) (length(dx) && !isTRUE(all.equal(dx, rep(dx[1], length(dx))))) || (length(dy) && !isTRUE(all.equal(dy, rep(dy[1], length(dy))))) } ``` the correct answer is obtained (i.e. that the input vector is not irregular based on the rational behind `all.equal`): ``` my_check_irregular(time, time) # FALSE ``` The same applies to POSIX* objects. I was wondering if this is intended or not? Thanks a lot for any answer, Chris [[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.