#' dateIndexToInteger
#'
-#' 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$getTime(1)[1])) ) ) + 1
#' integerIndexToDate
#'
-#' Transform an integer index to date index (relative to data)
+#' Transform an integer index (relative to data beginning) into a date index.
#'
-#' @param index Date (or integer) index
-#' @param data Object of class \code{Data}
+#' @inheritParams dateIndexToInteger
#'
#' @export
integerIndexToDate = function(index, data)
{
+ # Works on dates too: trust input
+ if (is.character(index))
+ index = as.Date(index)
+ if (is(index,"Date"))
+ return (index)
+
index = index[1]
if (is.numeric(index))
index = as.integer(index)
if (!is.integer(index))
- stop("'index' should be an integer")
+ stop("'index' should be a date or integer")
as.Date( data$getTime(index)[1] )
}
#' getSimilarDaysIndices
#'
-#' 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)
{
- index = dateIndexToInteger(index)
+ index = dateIndexToInteger(index, data)
- #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) )
- }
-
- #Look for similar days in similar season (+/- 30 days)
+ # Look for similar days (optionally in same season)
+ i = index - 1
days = c()
- i = index
+ 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 (i < index)
- {
- days = c(days, i)
- #look in the "future of the past"
- for (j in 1:4)
- days = c(days, i+7*j)
- }
- #...and in the "past of the past"
- for (j in 1:4)
+ dt = as.POSIXlt(data$getTime(i)[1])
+ if ((is.null(days_in) || i %in% days_in) && .isSameDay(dt$wday, day_ref))
{
- if (i - 7*j >= 1)
- days = c(days, i-7*j)
+ if (!same_season || .isSameSeason(dt$mon+1, month_ref))
+ days = c(days, i)
}
- # TODO: exact computation instead of -364
- # 364 = closest multiple of 7 to 365 - drift along the years... but not so many years so OK
- i = i - 364
+ i = i - 1
}
+ return ( days )
+}
- return ( days[1:min(limit,length(days))] )
+# isSameSeason
+#
+# Check if two months fall in the same "season" (defined by estimated pollution rate).
+#
+# @param month Month index to test
+# @param month_ref Month to compare to
+#
+.isSameSeason = function(month, month_ref)
+{
+ if (month_ref %in% c(11,12,1,2)) #~= mid-polluted
+ return (month %in% c(11,12,1,2))
+ if (month_ref %in% c(3,4,9,10)) #~= high-polluted
+ return (month %in% c(3,4,9,10))
+ return (month %in% c(5,6,7,8)) #~= non polluted
}
-#' getSerie
-#'
-#' Return a time-serie from its centered version + level
-#'
-#' @param data A list as returned by \code{getData}
-#' @param index The index to return
-#'
-#' @export
-getSerie = function(data, index)
- data[[index]]$centered_serie + data[[index]]$level
+# 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)
+}
projects / talweg.git / blobdiff