R/time.R

In five-dots/rutils: My R Utilities

#' Make lubridate duration object from HH:MM:SS string
#'
#' @param hhmmss character scalar of HH:MM:SS format
#'
#' @return lubridate's duration object
#' @export
make_duration <- function(hhmmss) {
  stopifnot(is.character(hhmmss),
            length(hhmmss) == 1,
            ## "HH:MM:SS" format
            stringr::str_count(hhmmss, ":") == 2)

  parts <- stringr::str_split(hhmmss, ":")[[1]] %>% as.numeric()
  lubridate::dhours(parts[1]) +
    lubridate::dminutes(parts[2]) +
    lubridate::dseconds(parts[3])
}

#' Make POSIXct from elapsed millisecond from epoch
#'
#' @param msec Elapsed milliseconds from epoch
#' @param tz Timezone
#'
#' @return POSIXct with millisecond accuracy
#' @export
make_dt_from_msec <- function(msec, tz = "America/New_York") {
  stopifnot(is.numeric(msec), length(msec) > 0,
            is.character(tz), length(tz) == 1)
  as.POSIXct(msec/1000, origin = "1970-01-01", tz = tz) + 0.0005
}

#' Make today's POSIXct of specified time and timezone
#'
#' @param hour Hour
#' @param min Minute
#' @param sec Second
#' @param tz Timezone
#'
#' @return POSIXct
#' @export
make_today_time <- function(hour = 0, min = 0, sec = 0,
                            tz = "America/New_York") {

  stopifnot(0 <= hour, hour < 24, length(hour) == 1,
            0 <= min, min < 60, length(min) == 1,
            0 <= sec, sec < 60, length(sec) == 1,
            is.character(tz), length(tz) == 1)

  td <- lubridate::today(tzone = tz)
  lubridate::make_datetime(lubridate::year(td),
                           lubridate::month(td),
                           lubridate::day(td),
                           hour, min, sec, tz = tz)
}