#' Find similar days indices in the past.
#'
#' @param index Day index (numeric or date)
+#' @param data Reference dataset, object output of \code{getData}
#' @param limit Maximum number of indices to return
#' @param same_season Should the indices correspond to day in same season?
-#' @param data Dataset is required for a search in same season
+#' @param days_in Optional set to intersect with results (NULL to discard)
#'
#' @export
-getSimilarDaysIndices = function(index, limit, same_season, data=NULL)
+getSimilarDaysIndices = function(index, data, limit, same_season, days_in=NULL)
{
- index = dateIndexToInteger(index)
+ index = dateIndexToInteger(index, data)
- #TODO: mardi similaire à lundi mercredi jeudi aussi ...etc ==> "isSimilarDay()..."
- if (!same_season)
- {
- #take all similar days in recent past
- nb_days = min( (index-1) %/% 7, limit)
- return ( rep(index,nb_days) - 7*seq_len(nb_days) )
- }
-
- #Look for similar days in similar season
- nb_days = min( (index-1) %/% 7, limit)
- i = index - 7
+ # Look for similar days (optionally in same season)
+ i = index - 1
days = c()
- month_ref = as.POSIXlt(data$getTime(index)[1])$mon + 1
+ dt_ref = as.POSIXlt(data$getTime(index)[1]) #first date-time of current day
+ day_ref = dt_ref$wday #1=monday, ..., 6=saturday, 0=sunday
+ month_ref = as.POSIXlt(data$getTime(index)[1])$mon+1 #month in 1...12
while (i >= 1 && length(days) < limit)
{
- if (isSameSeason(as.POSIXlt(data$getTime(i)[1])$mon + 1, month_ref))
- days = c(days, i)
- i = i-7
+ dt = as.POSIXlt(data$getTime(i)[1])
+ if ((is.null(days_in) || i %in% days_in) && .isSameDay(dt$wday, day_ref))
+ {
+ if (!same_season || .isSameSeason(dt$mon+1, month_ref))
+ days = c(days, i)
+ }
+ i = i - 1
}
return ( days )
}
-#TODO: use data... 12-12-1-2 CH, 3-4-9-10 EP et le reste NP
-isSameSeason = function(month, month_ref)
+# isSameSeason
+#
+# Check if two months fall in the same "season" (defined by estimated pollution rate)
+#
+# @param month month index to test
+# @param month_ref month to compare to
+#
+.isSameSeason = function(month, month_ref)
{
- if (month_ref %in% c(11,12,1,2))
+ if (month_ref %in% c(11,12,1,2)) #~= mid-polluted
return (month %in% c(11,12,1,2))
- if (month_ref %in% c(3,4,9,10))
+ if (month_ref %in% c(3,4,9,10)) #~= high-polluted
return (month %in% c(3,4,9,10))
- return (month %in% c(5,6,7,8))
+ return (month %in% c(5,6,7,8)) #~= non polluted
}
-#TODO:
-#distinction lun-jeudi, puis ven, sam, dim
-#isSameDay = function(day, day_ref)
-#{
-# if (day_ref ==
+# isSameDay
+#
+# Monday=Tuesday=Wednesday=Thursday ; Friday, Saturday, Sunday: specials
+#
+# @param day day index to test
+# @param day_ref day index to compare to
+#
+.isSameDay = function(day, day_ref)
+{
+ if (day_ref == 0)
+ return (day==0)
+ if (day_ref <= 4)
+ return (day <= 4)
+ return (day == day_ref)
+}
#' getNoNA2
#'