rename pkg --> talweg

[talweg.git] / talweg / R / utils.R

diff --git a/talweg/R/utils.R b/talweg/R/utils.R
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+#' dateIndexToInteger
+#'
+#' Transform a (potential) date index into an integer (relative to data)
+#'
+#' @param index Date (or integer) index
+#' @param data Object of class \code{Data}
+#'
+#' @export
+dateIndexToInteger = function(index, data)
+{
+       #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"))
+               #TODO: tz arg to difftime ?
+               integerIndex <- round( as.numeric(
+                       difftime(indexAsDate, as.Date(data$getTime(1)[1])) ) ) + 1
+               if (integerIndex >= 1 && integerIndex <= data$getSize())
+                       return (integerIndex)
+               stop("Date outside data range")
+       }
+       stop("Unrecognized index format")
+}
+
+#' integerIndexToDate
+#'
+#' Transform an integer index to date index (relative to data)
+#'
+#' @param index Date (or integer) index
+#' @param data Object of class \code{Data}
+#'
+#' @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 a date or integer")
+       as.Date( data$getTime(index)[1] )
+}
+
+#' getSimilarDaysIndices
+#'
+#' Find similar days indices in the past
+#'
+#' @param index Day index (numeric or date)
+#' @param limit Maximum number of indices to return
+#' @param same_seaon Should the indices correspond to day in same season?
+#'
+#' @export
+getSimilarDaysIndices = function(index, limit, same_season)
+{
+       index = dateIndexToInteger(index)
+
+       #TODO: mardi similaire à lundi mercredi jeudi aussi ...etc
+       if (!same_season)
+       {
+               #take all similar days in recent past
+               nb_days = min( (index-1) %/% 7, limit)
+               return ( rep(index,nb_days) - 7*seq_len(nb_days) )
+       }
+
+       #Look for similar days in similar season (+/- 30 days)
+       days = c()
+       i = index
+       while (i >= 1 && length(days) < limit)
+       {
+               if (i < index)
+               {
+                       days = c(days, i)
+                       #look in the "future of the past"
+                       for (j in 1:4)
+                               days = c(days, i+7*j)
+               }
+               #...and in the "past of the past"
+               for (j in 1:4)
+               {
+                       if (i - 7*j >= 1)
+                               days = c(days, i-7*j)
+               }
+               # TODO: exact computation instead of -364
+               # 364 = closest multiple of 7 to 365 - drift along the years... but not so many years so OK
+               i = i - 364
+       }
+
+       return ( days[1:min(limit,length(days))] )
+}
+
+#' getSerie
+#'
+#' Return a time-serie from its centered version + level
+#'
+#' @param data A list as returned by \code{getData}
+#' @param index The index to return
+#'
+#' @export
+getSerie = function(data, index)
+       data[[index]]$centered_serie + data[[index]]$level
+
+#' getNoNA2
+#'
+#' Get indices in data of no-NA series followed by no-NA, within [first,last] range.
+#'
+#' @param data Object of class Data
+#' @param first First index (included)
+#' @param last Last index (included)
+#'
+#' @export
+getNoNA2 = function(data, first, last)
+{
+       (first:last)[ sapply(first:last, function(i)
+               !any( is.na(data$getCenteredSerie(i)) | is.na(data$getCenteredSerie(i+1)) )
+       ) ]
+}