R/raws_filterDate.R

In MazamaScience/RAWSmet: Download and Process data from Remote Automatic Weather Stations

#' @export
#' @importFrom rlang .data
#'
#' @title Date filtering for \emph{raws_timeseries} objects
#'
#' @param rawsObject \emph{raws_timeseries} object.
#' @param startdate Desired start datetime (ISO 8601).
#' @param enddate Desired end datetime (ISO 8601).
#' @param timezone Olson timezone used to interpret dates.
#' @param unit Units used to determine time at end-of-day.
#' @param ceilingStart Logical instruction to apply
#'   \code{\link[lubridate]{ceiling_date}} to the \code{startdate} rather than
#'   \code{\link[lubridate]{floor_date}}
#' @param ceilingEnd Logical instruction to apply
#'   \code{\link[lubridate]{ceiling_date}} to the \code{enddate} rather than
#'   \code{\link[lubridate]{floor_date}}
#'
#' @return A subset of the given \emph{raws_timeseries} object.
#'
#' @description Subsets a \emph{raws_timeseries} object by date. This function
#' always filters to day-boundaries.
#'
#' Dates can be anything that is understood by \code{lubridate::ymd()}
#' including either of the following recommended formats:
#'
#' \itemize{
#' \item{\code{"YYYYmmdd"}}
#' \item{\code{"YYYY-mm-dd"}}
#' }
#'
#' @note The returned data will run from the beginning of \code{startdate} until
#' the \strong{beginning} of \code{enddate} -- \emph{i.e.} no values associated
#' with \code{enddate} will be returned. The exception being when
#' \code{enddate} is less than 24 hours after \code{startdate}. In that case, a
#' single day is returned.
#'
#' @seealso \link{raws_filter}
#' @examples
#' \donttest{
#' library(RAWSmet)
#'
#' data201708 <-
#'   example_cefa_Saddle_Mountain %>%
#'   raws_filterDate(20170801, 20170901, timezone = "America/Los_Angeles")
#'
#' head(data201708$data)
#' }
#'
raws_filterDate <- function(
  rawsObject = NULL,
  startdate = NULL,
  enddate = NULL,
  timezone = NULL,
  unit = "sec",
  ceilingStart = FALSE,
  ceilingEnd = FALSE
) {

  # ----- Validate parameters --------------------------------------------------

  MazamaCoreUtils::stopIfNull(rawsObject)

  if ( !raws_isRaws(rawsObject) )
    stop("Parameter 'rawsObject' is not a valid 'raws_timeseries' object.")

  if ( raws_isEmpty(rawsObject) )
    stop("Parameter 'rawsObject' has no data.")

  # Remove any duplicate data records
  rawsObject <- raws_distinct(rawsObject)

  if ( is.null(startdate) && !is.null(enddate) )
    stop("At least one of 'startdate' or 'enddate' must be specified")

  # Timezone determination precedence assumes that if you are passing in
  # POSIXct times then you know what you are doing.
  #   1) get timezone from startdate if it is POSIXct
  #   2) use passed in timezone
  #   3) get timezone from rawsObject

  if ( lubridate::is.POSIXt(startdate) ) {
    timezone <- lubridate::tz(startdate)
  } else {
    if ( is.null(timezone) ) {
      timezone <- rawsObject$meta$timezone
    }
  }

  # ----- Call MazamaTimeSeries function ---------------------------------------

  rawsObject <-
    MazamaTimeSeries::sts_filterDate(
      sts = rawsObject,
      startdate = startdate,
      enddate = enddate,
      timezone = timezone,
      unit = unit,
      ceilingStart = ceilingStart,
      ceilingEnd = ceilingEnd
    )

  class(rawsObject) <- union("raws_timeseries", class(rawsObject))

  # ----- Return ---------------------------------------------------------------

  return(rawsObject)

}