'update'
[talweg.git] / pkg / R / utils.R
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25b75559 1#' dateIndexToInteger
3d69ff21 2#'
25b75559 3#' Transform a (potential) date index into an integer (relative to data)
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4#'
5#' @param index Date (or integer) index
6#' @param data Object of class \code{Data}
7#'
8#' @export
9dateIndexToInteger = function(index, data)
10{
98e958ca 11 #works on integers too: trust input
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12 if (is.numeric(index))
13 index = as.integer(index)
3d69ff21 14 if (is.integer(index))
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15 return (index)
16
09cf9c19 17 if (inherits(index, "Date") || is.character(index))
3d69ff21 18 {
44a9990b 19 tryCatch(indexAsDate <- as.Date(index), error=function(e) stop("Unrecognized index format"))
3d69ff21 20 #TODO: tz arg to difftime ?
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21 integerIndex <- round( as.numeric(
22 difftime(indexAsDate, as.Date(data$getTime(1)[1])) ) ) + 1
23 if (integerIndex >= 1 && integerIndex <= data$getSize())
25b75559 24 return (integerIndex)
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25 stop("Date outside data range")
26 }
27 stop("Unrecognized index format")
28}
29
25b75559 30#' integerIndexToDate
09cf9c19 31#'
25b75559 32#' Transform an integer index to date index (relative to data)
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33#'
34#' @param index Date (or integer) index
35#' @param data Object of class \code{Data}
36#'
37#' @export
38integerIndexToDate = function(index, data)
39{
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40 #works on dates too: trust input
41 if (is.character(index))
42 index = as.Date(index)
a66a84b5 43 if (is(index,"Date"))
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44 return (index)
45
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46 index = index[1]
47 if (is.numeric(index))
48 index = as.integer(index)
49 if (!is.integer(index))
a66a84b5 50 stop("'index' should be a date or integer")
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51 as.Date( data$getTime(index)[1] )
52}
53
25b75559 54#' getSimilarDaysIndices
3d69ff21 55#'
4e25de2c 56#' Find similar days indices in the past.
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57#'
58#' @param index Day index (numeric or date)
59#' @param limit Maximum number of indices to return
4e25de2c 60#' @param same_season Should the indices correspond to day in same season?
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61#'
62#' @export
63getSimilarDaysIndices = function(index, limit, same_season)
64{
65 index = dateIndexToInteger(index)
66
67 #TODO: mardi similaire à lundi mercredi jeudi aussi ...etc
68 if (!same_season)
69 {
70 #take all similar days in recent past
71 nb_days = min( (index-1) %/% 7, limit)
72 return ( rep(index,nb_days) - 7*seq_len(nb_days) )
73 }
74
75 #Look for similar days in similar season (+/- 30 days)
76 days = c()
77 i = index
78 while (i >= 1 && length(days) < limit)
79 {
80 if (i < index)
81 {
82 days = c(days, i)
83 #look in the "future of the past"
84 for (j in 1:4)
85 days = c(days, i+7*j)
86 }
87 #...and in the "past of the past"
88 for (j in 1:4)
89 {
90 if (i - 7*j >= 1)
91 days = c(days, i-7*j)
92 }
93 # TODO: exact computation instead of -364
94 # 364 = closest multiple of 7 to 365 - drift along the years... but not so many years so OK
95 i = i - 364
96 }
97
98 return ( days[1:min(limit,length(days))] )
99}
25b75559 100
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101#' getNoNA2
102#'
103#' Get indices in data of no-NA series followed by no-NA, within [first,last] range.
104#'
105#' @param data Object of class Data
106#' @param first First index (included)
107#' @param last Last index (included)
108#'
109#' @export
110getNoNA2 = function(data, first, last)
111{
112 (first:last)[ sapply(first:last, function(i)
113 !any( is.na(data$getCenteredSerie(i)) | is.na(data$getCenteredSerie(i+1)) )
114 ) ]
115}