| 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 | index = index[1] |
| 12 | if (is.numeric(index)) |
| 13 | index = as.integer(index) |
| 14 | if (is.integer(index)) |
| 15 | return (index) |
| 16 | if (inherits(index, "Date") || is.character(index)) |
| 17 | { |
| 18 | tryCatch(dt <- as.POSIXct(index), error=function(e) stop("Unrecognized index format")) |
| 19 | #TODO: tz arg to difftime ? |
| 20 | integerIndex <- round( (as.numeric( difftime(dt, data$getTime(1)) ))[1] ) + 1 |
| 21 | if (integerIndex > 0 && integerIndex <= data$getSize()) |
| 22 | { |
| 23 | #WARNING: if series start at date >0h, result must be shifted |
| 24 | date1 = as.POSIXlt(data$getTime(1)[1]) |
| 25 | date2 = as.POSIXlt(data$getTime(2)[1]) |
| 26 | shift = (date1$year==date2$year && date1$mon==date2$mon && date1$mday==date2$mday) |
| 27 | return (integerIndex + ifelse(shift,1,0)) |
| 28 | } |
| 29 | stop("Date outside data range") |
| 30 | } |
| 31 | stop("Unrecognized index format") |
| 32 | } |
| 33 | |
| 34 | #' @title integerIndexToDate |
| 35 | #' |
| 36 | #' @description Transform an integer index to date index (relative to data) |
| 37 | #' |
| 38 | #' @param index Date (or integer) index |
| 39 | #' @param data Object of class \code{Data} |
| 40 | #' |
| 41 | #' @export |
| 42 | integerIndexToDate = function(index, data) |
| 43 | { |
| 44 | index = index[1] |
| 45 | if (is.numeric(index)) |
| 46 | index = as.integer(index) |
| 47 | if (!is.integer(index)) |
| 48 | stop("'index' should be an integer") |
| 49 | as.Date( data$getTime(index)[1] ) |
| 50 | } |
| 51 | |
| 52 | #' @title getSimilarDaysIndices |
| 53 | #' |
| 54 | #' @description Find similar days indices in the past |
| 55 | #' |
| 56 | #' @param index Day index (numeric or date) |
| 57 | #' @param limit Maximum number of indices to return |
| 58 | #' @param same_seaon Should the indices correspond to day in same season? |
| 59 | #' |
| 60 | #' @export |
| 61 | getSimilarDaysIndices = function(index, limit, same_season) |
| 62 | { |
| 63 | index = dateIndexToInteger(index) |
| 64 | |
| 65 | #TODO: mardi similaire à lundi mercredi jeudi aussi ...etc |
| 66 | if (!same_season) |
| 67 | { |
| 68 | #take all similar days in recent past |
| 69 | nb_days = min( (index-1) %/% 7, limit) |
| 70 | return ( rep(index,nb_days) - 7*seq_len(nb_days) ) |
| 71 | } |
| 72 | |
| 73 | #Look for similar days in similar season (+/- 30 days) |
| 74 | days = c() |
| 75 | i = index |
| 76 | while (i >= 1 && length(days) < limit) |
| 77 | { |
| 78 | if (i < index) |
| 79 | { |
| 80 | days = c(days, i) |
| 81 | #look in the "future of the past" |
| 82 | for (j in 1:4) |
| 83 | days = c(days, i+7*j) |
| 84 | } |
| 85 | #...and in the "past of the past" |
| 86 | for (j in 1:4) |
| 87 | { |
| 88 | if (i - 7*j >= 1) |
| 89 | days = c(days, i-7*j) |
| 90 | } |
| 91 | # TODO: exact computation instead of -364 |
| 92 | # 364 = closest multiple of 7 to 365 - drift along the years... but not so many years so OK |
| 93 | i = i - 364 |
| 94 | } |
| 95 | |
| 96 | return ( days[1:min(limit,length(days))] ) |
| 97 | } |