R/date_timeserie.R

In jeanmarie-eu/timeManip: time data manipulation

#' Make a timeserie of dates
#'
#' The fuction \code{dateTimeSerie()} builds the timeserie of date
#' @param timeResolution "daily","hourly","minute","second"
#' @param v multiplicative coefficient to the timeResolution
#' @param fromPeriod date char "YYYYmmddH..."
#' @param toPeriod date char "YYYYmmdd..."
#' @param precision "daily","hourly","minute","second",...
#' @return The output is a list of a timeserie of POSIXct and the number of steps
#' @keywords timeManip
#' @export
#' @examples
#' res <- timeserie(timeResolution = "hourly",fromPeriod="2015010100",toPeriod="2015010322")
#' head(res)
#' res <- timeserie("daily","1980022802","1980030102","hourly")
#' head(res)
#' res <- timeserie("hourly",v=2,"1980022802","1980030102","hourly")
#' head(res)
timeserie <- function(timeResolution,fromPeriod,toPeriod,precision=NULL,v=1){

  if (is.null(precision) && (timeResolution!="three-hourly")) {
    precision <- timeResolution
  } else if(is.null(precision) && (timeResolution=="three-hourly")) {
    precision <- "hourly"
  }

  from_POSIXlt <- standard(precision,fromPeriod)
  to_POSIXlt   <- standard(precision,toPeriod)

  seqPeriod <- switch(timeResolution,
    "yearly"       = seq(from = from_POSIXlt, to = to_POSIXlt, by = "year"),
    "monthly"      = seq(from = from_POSIXlt, to = to_POSIXlt, by = "month"),
    "daily"        = seq(from = from_POSIXlt, to = to_POSIXlt, by = (v*24*3600)),
    "three-hourly" = seq(from = from_POSIXlt, to = to_POSIXlt, by = (v*3*3600)),
    "hourly"       = seq(from = from_POSIXlt, to = to_POSIXlt, by = (v*3600)),
    "minute"       = seq(from = from_POSIXlt, to = to_POSIXlt, by = (v*60)),
    "second"       = seq(from = from_POSIXlt, to = to_POSIXlt, by = (v*1)),
    (stop(paste0("Invalid time resolution:", timeResolution,".")))
  )

  nbStep=length(seqPeriod)

  res <- list(nbStep=length(seqPeriod),
              seqPeriod=as.POSIXlt(seqPeriod,tz = "GMT"))

  return(res)
}