R/get_season.R

In edwardpmorris/FASTSpectra: Parse and radiometrically correct Ocean Optics spectra files

#' Asign astronomical seasons
#'
#' @param DATES The dates to be binned into seasons 
#'
#' @return A character vector of seasons
#' @export
#'
#' @examples getSeason(c("2012-1-15", "2009-4-1", "2015-7-21", "2011-10-21"))
getSeason <- function(DATES) {
  WS <- as.Date("2012-12-21", format = "%Y-%m-%d") # Winter Solstice
  SE <- as.Date("2012-3-21",  format = "%Y-%m-%d") # Spring Equinox
  SS <- as.Date("2012-6-21",  format = "%Y-%m-%d") # Summer Solstice
  FE <- as.Date("2012-9-21",  format = "%Y-%m-%d") # Fall Equinox
  
  # Convert dates from any year to 2012 dates
  d <- as.Date(strftime(DATES, format="2012-%m-%d"))
  
  ifelse (d >= WS | d < SE, "Winter",
          ifelse (d >= SE & d < SS, "Spring",
                  ifelse (d >= SS & d < FE, "Summer", "Fall")))
}