R/timeFloor.R

In Agriculturist/EmissionsHelper: Emissions Modeling Support Functions Package

#' timeFloor
#'
#' This function acts like a floor function execpt for time.
#'
#' @param timeValue typically a column of time Values to take the floor function
#' @param timeIntervalValue the value of the time interval
#' @param timeIntervalUnits the units of the time interval
#' @keywords time
#' @examples
#' 
#' library(EmissionsHelper)
#' mytime <- reformatTime(c("2018-1-1 12:01", "2018-1-1 12:02",
#'                        "2018-1-1 12:16", "2018-1-1 12:17")) 
#' timeFloor(mytime, 15, "minutes") 
#'
#' @export

timeFloor <- function(timeValue, timeIntervalValue = 15, timeIntervalUnits = "minutes"){
  
  timeIntervalInSeconds <- switch(timeIntervalUnits,
                                  "seconds" = 1,
                                  "second" = 1,
                                  "sec" = 1,
                                  "s" = 1,
                                  "minutes" = 60,
                                  "minute" = 60,
                                  "min" = 60,
                                  "m" = 60,
                                  "hours" = 3600,
                                  "hour" = 3600,
                                  "hr" = 3600,
                                  "h" = 3600)
  
  if(!is.null(timeValue)){
    return(as.POSIXct(floor(as.numeric(as.POSIXct(timeValue)) / 
                              (timeIntervalValue * timeIntervalInSeconds)) * 
                        (timeIntervalValue * timeIntervalInSeconds), 
                      origin='1970-01-01'))
  }else{
    warning("Check parameters in timeFloor function ... timeValue is NULL")
  }
  
  
}