Handling Feb29 in date_to_doy, so that user can choose if to report F…

…eb29 as day 61 (skip_feb29 = F) or as 60 (skip_feb29 = T) and treat all consequent days accordingly. In case of skip_feb29 = T, DOY 60 will be repeated twice for Feb 28 and 29.

cropCalendars/R/calcMonthlyClimate.R

@@ -10,6 +10,7 @@
 #' in form of a vector.
 #' @param syear start year in the climate time series.
 #' @param eyear end yeat in the climate time series.
+#' @param incl_feb29 time series include February 29th in leap years?
 #' @examples
 #' d_temp <- matrix(rnorm(365*3, 15), nrow = 3)
 #' d_prec <- matrix(rnorm(365*3, 3, 50), nrow = 3)
@@ -23,26 +24,25 @@ calcMonthlyClimate <- function(lat        = NULL,
                                prec       = NULL,
                                syear      = NULL,
                                eyear      = NULL,
-                               leap_years = TRUE
+                               incl_feb29 = TRUE
                                ) {
 
   years   <- syear:eyear
   nyears  <- length(years)
-  days    <- seq_len(365)
-  ndays   <- length(days)
   nmonths <- 12
 
-  if (leap_years == FALSE) {
+  if (incl_feb29 == FALSE) {
     dates <- createDateSeq(nstep = 365, years = years)
 
   } else {
     dates <- seqDates(start_date = paste0(syear, "-01-01"),
                       end_date   = paste0(eyear, "-12-31"),
                       step       = "day")
   }
-  d_dates <- date_to_doy(dates)
-  m_dates <- date_to_month(dates)
   y_dates <- date_to_year(dates)
+  m_dates <- date_to_month(dates)
+  d_dates <- date_to_doy(dates, skip_feb29 = TRUE)
+
 
   # Compute PET (Potential ET)
   cat("Computing daily PET ...\n")

cropCalendars/R/zz_dates.R

@@ -55,39 +55,65 @@ createDateSeq <- function(nstep = 365,
 # Create sequence of dates and return as character
 seqDates <- function(start_date = "1980-01-01",
                      end_date   = "1980-12-31",
-                     step       = "day") {
+                     step       = "day"
+                     ) {
   as.character(
     seq.Date(from = as.Date(start_date),
              to   = as.Date(end_date),
              by   = step)
   )
 }
 
+# Check if date is 29th February
+is29Feb <- function(date = "1980-01-01"
+                    ) {
+  day <- format(as.Date(date), "%d")
+  mon <- format(as.Date(date), "%m")
+
+  return(paste(mon, day) == "02 29")
+}
+
 # Convert day-of-the-year (DOY) to date "YYYY-MM-DD"
 doy_to_date <- function(doy  = NULL,
                         year = NULL
-) {
+                        ) {
   if (length(doy) != length(year)) stop("doy and year have different length")
 
-  date <- strptime(paste(year, doy), format="%Y %j")
+  date <- strptime(paste(year, doy), format = "%Y %j")
   return(date)
 }
 
 # Convert date "YYYY-MM-DD" to day-of-the-year (DOY)
-date_to_doy <- function(date = "2010-01-29"
-) {
-  as.integer(format(as.Date(date), "%j"))
+date_to_doy <- function(date       = "2010-01-29",
+                        skip_feb29 = TRUE
+                        ) {
+
+  if (skip_feb29 == TRUE) {
+    # What DOY is Dec. 31 for the year of date, 365 or 366?
+    dec31 <- paste(format(as.Date(date), "%Y"), "12-31", sep = "-")
+    doy_dec31 <- as.integer(format(as.Date(dec31), "%j"))
+    # Convert date to DOY, including Feb. 29
+    doy1 <- as.integer(format(as.Date(date), "%j"))
+    # If is leap year, subtract 1 to all DOYs after Feb. 28
+    doy <- ifelse(doy_dec31 == 366 & doy1 > 28,
+                  doy1 - 1,
+                  doy1)
+  } else {
+    # Just convert date to DOY, including Feb. 29
+    doy <- as.integer(format(as.Date(date), "%j"))
+  }
+  return(doy)
 }
 
 # Convert date "YYYY-MM-DD" to day-of-the-year (DOY)
 date_to_month <- function(date = "2010-01-29"
-) {
+                          ) {
   as.integer(format(as.Date(date), "%m"))
 }
 
 # Convert date "YYYY-MM-DD" to day-of-the-year (DOY)
 date_to_year <- function(date = "2010-01-29"
-) {
+                         ) {
   as.integer(format(as.Date(date), "%Y"))
 }