R/dayte.R

In poissonconsulting/poisix: Manipulate Datetimes

#' Get Day of the Year
#'
#' Returns the day of the year as an integer between 1 and 366.
#'
#' @param x The object.
#' @return An integer vector with values between 1 and 366.
#' @export
#' @examples
#' doy(as.Date("2002-01-11"))
#' doy(as.Date("2001-05-16"))
doy <- function(x){
  chkor(check_values(x, c(Sys.Date(), NA)), check_values(x, c(Sys.time(), NA)))
  x %<>% dtt_date()
  y <- as.Date(paste(dtt_year(x) - 1, 12, 31, sep = "-"))
  x %<>% difftime(y, units = "days") %>% as.integer()
  x
}

#' Day of the Year as an integer to a Date
#'
#' @param x The integer vector
#' @param year An integer vector of the year(s)
#' @return A Date vector.
#' @export
#' @examples
#' doy2date(1:2, 2000)
#' doy2date(1:2, 2002:2001)
doy2date <- function(x, year){
  chk_whole_numeric(x)
  chk_whole_numeric(year)
  chk_range(x, c(1, 366))
  chk_not_any_na(year)

  if(!length(x)) return(as.Date(character(0)))

  x + as.Date(paste0(year - 1, "-12-31"))
}

#' Get Day of the year as a Date
#'
#' Returns the day of the year as a Date by setting the
#' year to be 1972 (as a leap year with two leap seconds)
#'
#' @param x The object.
#' @return A Date or POSIXt object.
#' @export
#' @examples
#' dayte(as.Date("2001-05-16"))
#' dayte(as.Date("2004-02-29"))
dayte <- function(x){
  chkor(check_values(x, c(Sys.Date(), NA)),
        check_values(x, c(Sys.time(), NA)))
  x %<>% dtt_date()
  dtt_year(x) <- 1972
  x
}

#' Get Day and time of the year as a POSIX
#'
#' Returns the day of the year as a Date by setting the
#' year to be 1972 (as a leap year with two leap seconds)
#'
#' @param x A POSIXt object.
#' @return A Date object.
#' @export
#' @examples
#' dayte_time(as.POSIXct("2001-05-16 02:03:04"))
dayte_time <- function(x){
  check_values(x, c(Sys.time(), NA))
  dtt_year(x) <- 1972
  x
}