| 1 | #' @title dateIndexToInteger |
| 2 | #' |
| 3 | #' @description Transform a (potential) date index into an integer (relative to data) |
| 4 | #' |
| 5 | #' @param index Date (or integer) index |
| 6 | #' @param data Object of class \code{Data} |
| 7 | #' |
| 8 | #' @export |
| 9 | dateIndexToInteger = function(index, data) |
| 10 | { |
| 11 | if (is.numeric(index)) |
| 12 | index = as.integer(index) |
| 13 | #Undocumented "private" method to translate index --> date (is needed) |
| 14 | if (is.integer(index)) |
| 15 | return (index[1]) |
| 16 | if (is.character(index)) |
| 17 | { |
| 18 | tryCatch(dt <- as.POSIXct(index[1]), finally=print("Unrecognized index format")) |
| 19 | #TODO: tz arg to difftime ? |
| 20 | integerIndex <- as.integer( difftime(dt, data$getTime(1)) ) + 1 |
| 21 | if (integerIndex > 0 && integerIndex <= data$getSize()) |
| 22 | return (integerIndex) |
| 23 | stop("Date outside data range") |
| 24 | } |
| 25 | stop("Unrecognized index format") |
| 26 | } |
| 27 | |
| 28 | #' @title getSimilarDaysIndices |
| 29 | #' |
| 30 | #' @description Find similar days indices in the past |
| 31 | #' |
| 32 | #' @param index Day index (numeric or date) |
| 33 | #' @param limit Maximum number of indices to return |
| 34 | #' @param same_seaon Should the indices correspond to day in same season? |
| 35 | #' |
| 36 | #' @export |
| 37 | getSimilarDaysIndices = function(index, limit, same_season) |
| 38 | { |
| 39 | index = dateIndexToInteger(index) |
| 40 | |
| 41 | #TODO: mardi similaire à lundi mercredi jeudi aussi ...etc |
| 42 | if (!same_season) |
| 43 | { |
| 44 | #take all similar days in recent past |
| 45 | nb_days = min( (index-1) %/% 7, limit) |
| 46 | return ( rep(index,nb_days) - 7*seq_len(nb_days) ) |
| 47 | } |
| 48 | |
| 49 | #Look for similar days in similar season (+/- 30 days) |
| 50 | days = c() |
| 51 | i = index |
| 52 | while (i >= 1 && length(days) < limit) |
| 53 | { |
| 54 | if (i < index) |
| 55 | { |
| 56 | days = c(days, i) |
| 57 | #look in the "future of the past" |
| 58 | for (j in 1:4) |
| 59 | days = c(days, i+7*j) |
| 60 | } |
| 61 | #...and in the "past of the past" |
| 62 | for (j in 1:4) |
| 63 | { |
| 64 | if (i - 7*j >= 1) |
| 65 | days = c(days, i-7*j) |
| 66 | } |
| 67 | # TODO: exact computation instead of -364 |
| 68 | # 364 = closest multiple of 7 to 365 - drift along the years... but not so many years so OK |
| 69 | i = i - 364 |
| 70 | } |
| 71 | |
| 72 | return ( days[1:min(limit,length(days))] ) |
| 73 | } |