R/which.R

In rformassspectrometry/MsCoreUtils: Core Utils for Mass Spectrometry Data

#' @title Which is the first/last TRUE value.
#'
#' @description
#'
#' Determines the location, i.e., index of the first or last `TRUE`
#' value in a logical vector.
#'
#' @param x `logical`, vector.
#' @return `integer`, index of the first/last `TRUE`
#'     value. `integer(0)` if no `TRUE` (everything `FALSE` or `NA`)
#'     was found.
#'
#' @rdname which
#' @author Sebastian Gibb
#' @seealso [`which.min()`]
#' @family helper functions for developers
#' @useDynLib MsCoreUtils, .registration = TRUE
#' @export
#' @examples
#' l <- 2 <= 1:3
#' which.first(l)
which.first <- function(x).Call(C_which_first, x)

#' @rdname which
#' @export
#' @examples
#' which.last(l)
which.last <- function(x).Call(C_which_last, x)