X-Git-Url: https://git.auder.net/?a=blobdiff_plain;f=pkg%2FR%2Futils.R;h=bb769967b328edba87f583b74eabb2e4df54a916;hb=638f27f4296727aff62b56643beb9f42aa5b57ef;hp=de8e861cb5c02ab5e0e2c1bc2f26f527b1c34589;hpb=44a9990b6d608ffcd2e99d5193fa8b9e6cbdb436;p=talweg.git

diff --git a/pkg/R/utils.R b/pkg/R/utils.R
index de8e861..bb76996 100644
--- a/pkg/R/utils.R
+++ b/pkg/R/utils.R
@@ -1,103 +1,148 @@
-#' @title dateIndexToInteger
+#' dateIndexToInteger
 #'
-#' @description Transform a (potential) date index into an integer (relative to data)
+#' Transform a (potential) date index into an integer (relative to data beginning).
 #'
 #' @param index Date (or integer) index
-#' @param data Object of class \code{Data}
+#' @param data Object of class Data, output of \code{getData()}
 #'
 #' @export
 dateIndexToInteger = function(index, data)
 {
-	index = index[1]
+	# Works on integers too: trust input
 	if (is.numeric(index))
 		index = as.integer(index)
 	if (is.integer(index))
 		return (index)
+
 	if (inherits(index, "Date") || is.character(index))
 	{
-		tryCatch(indexAsDate <- as.Date(index), error=function(e) stop("Unrecognized index format"))
+		tryCatch(indexAsDate <- as.Date(index),
+			error=function(e) stop("Unrecognized index format"))
 		#TODO: tz arg to difftime ?
 		integerIndex <- round( as.numeric(
 			difftime(indexAsDate, as.Date(data$getTime(1)[1])) ) ) + 1
 		if (integerIndex >= 1 && integerIndex <= data$getSize())
-		{
-			#WARNING: if index>=2 && series start at date >0h, result must be shifted
-			#Convention: if first date asked, return first matching index (i.e.: 1)
-			shift = 0
-			if (integerIndex >= 2)
-			{
-				date1 = as.POSIXlt(data$getTime(1)[1])
-				date2 = as.POSIXlt(data$getTime(2)[1])
-				shift = (date1$year==date2$year && date1$mon==date2$mon && date1$mday==date2$mday)
-			}
-			return (integerIndex + shift)
-		}
+			return (integerIndex)
 		stop("Date outside data range")
 	}
 	stop("Unrecognized index format")
 }
 
-#' @title integerIndexToDate
+#' integerIndexToDate
 #'
-#' @description Transform an integer index to date index (relative to data)
+#' Transform an integer index (relative to data beginning) into a date index.
 #'
-#' @param index Date (or integer) index
-#' @param data Object of class \code{Data}
+#' @inheritParams dateIndexToInteger
 #'
 #' @export
 integerIndexToDate = function(index, data)
 {
+	# Works on dates too: trust input
+	if (is.character(index))
+		index = as.Date(index)
+	if (is(index,"Date"))
+		return (index)
+
 	index = index[1]
 	if (is.numeric(index))
 		index = as.integer(index)
 	if (!is.integer(index))
-		stop("'index' should be an integer")
+		stop("'index' should be a date or integer")
 	as.Date( data$getTime(index)[1] )
 }
 
-#' @title getSimilarDaysIndices
+#' getSimilarDaysIndices
 #'
-#' @description Find similar days indices in the past
+#' Find similar days indices in the past; at least same type of day in the week:
+#' monday=tuesday=wednesday=thursday != friday != saturday != sunday.
 #'
 #' @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_seaon Should the indices correspond to day in same season?
+#' @param same_season Should the indices correspond to day in same season?
+#' @param days_in Optional set to intersect with results (NULL to discard)
 #'
 #' @export
-getSimilarDaysIndices = function(index, limit, same_season)
+getSimilarDaysIndices = function(index, data, limit, same_season,
+	days_in=NULL, operational=TRUE)
 {
-	index = dateIndexToInteger(index)
-
-	#TODO: mardi similaire à lundi mercredi jeudi aussi ...etc
-	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) )
-	}
+	index = dateIndexToInteger(index, data)
 
-	#Look for similar days in similar season (+/- 30 days)
+	# Look for similar days (optionally in same season)
 	days = c()
-	i = index
-	while (i >= 1 && length(days) < limit)
+	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
+	i = index - 1
+	if (!operational)
+		j = index + 1
+	while (length(days) < min( limit, ifelse(is.null(days_in),Inf,length(days_in)) ))
 	{
-		if (i < index)
+		if (i >= 1)
 		{
-			days = c(days, i)
-			#look in the "future of the past"
-			for (j in 1:4)
-				days = c(days, i+7*j)
+			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$mon+1, month_ref))
+					days = c(days, i)
+			}
+			i = i - 1
 		}
-		#...and in the "past of the past"
-		for (j in 1:4)
+		if (!operational && j <= data$getSize())
 		{
-			if (i - 7*j >= 1)
-				days = c(days, i-7*j)
+			dt = as.POSIXlt(data$getTime(j)[1])
+			if ((is.null(days_in) || j %in% days_in) && .isSameDay(dt$wday, day_ref))
+			{
+				if (!same_season || .isSameSeason(dt$mon+1, month_ref))
+					days = c(days, j)
+			}
+			j = j + 1
 		}
-		# TODO: exact computation instead of -364
-		# 364 = closest multiple of 7 to 365 - drift along the years... but not so many years so OK
-		i = i - 364
 	}
+	return ( days )
+}
+
+# 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)) #~= mid-polluted
+		return (month %in% c(11,12,1,2))
+	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)) #~= non polluted
+}
+
+# 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 %in% 1:4)
+		return (day %in% 1:4)
+	return (day == day_ref)
+}
 
-	return ( days[1:min(limit,length(days))] )
+# getNoNA2
+#
+# Get indices in data of no-NA series preceded by no-NA, within [first,last] range.
+#
+# @inheritParams dateIndexToInteger
+# @param first First index (included)
+# @param last Last index (included)
+#
+.getNoNA2 = function(data, first, last)
+{
+	(first:last)[ sapply(first:last, function(i)
+		!any( is.na(data$getSerie(i-1)) | is.na(data$getSerie(i)) )
+	) ]
 }