64c3c0a1b5c586e009cc8ae44ff271a0c1a7f2b1
[talweg.git] / pkg / R / utils.R
1 #' dateIndexToInteger
2 #'
3 #' 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 #works on integers too: trust input
12 if (is.numeric(index))
13 index = as.integer(index)
14 if (is.integer(index))
15 return (index)
16
17 if (inherits(index, "Date") || is.character(index))
18 {
19 tryCatch(indexAsDate <- as.Date(index), error=function(e) stop("Unrecognized index format"))
20 #TODO: tz arg to difftime ?
21 integerIndex <- round( as.numeric(
22 difftime(indexAsDate, as.Date(data$getTime(1)[1])) ) ) + 1
23 if (integerIndex >= 1 && integerIndex <= data$getSize())
24 return (integerIndex)
25 stop("Date outside data range")
26 }
27 stop("Unrecognized index format")
28 }
29
30 #' integerIndexToDate
31 #'
32 #' Transform an integer index to date index (relative to data)
33 #'
34 #' @param index Date (or integer) index
35 #' @param data Object of class \code{Data}
36 #'
37 #' @export
38 integerIndexToDate = function(index, data)
39 {
40 #works on dates too: trust input
41 if (is.character(index))
42 index = as.Date(index)
43 if (is(index,"Date"))
44 return (index)
45
46 index = index[1]
47 if (is.numeric(index))
48 index = as.integer(index)
49 if (!is.integer(index))
50 stop("'index' should be a date or integer")
51 as.Date( data$getTime(index)[1] )
52 }
53
54 #' getSimilarDaysIndices
55 #'
56 #' Find similar days indices in the past
57 #'
58 #' @param index Day index (numeric or date)
59 #' @param limit Maximum number of indices to return
60 #' @param same_seaon Should the indices correspond to day in same season?
61 #'
62 #' @export
63 getSimilarDaysIndices = function(index, limit, same_season)
64 {
65 index = dateIndexToInteger(index)
66
67 #TODO: mardi similaire à lundi mercredi jeudi aussi ...etc
68 if (!same_season)
69 {
70 #take all similar days in recent past
71 nb_days = min( (index-1) %/% 7, limit)
72 return ( rep(index,nb_days) - 7*seq_len(nb_days) )
73 }
74
75 #Look for similar days in similar season (+/- 30 days)
76 days = c()
77 i = index
78 while (i >= 1 && length(days) < limit)
79 {
80 if (i < index)
81 {
82 days = c(days, i)
83 #look in the "future of the past"
84 for (j in 1:4)
85 days = c(days, i+7*j)
86 }
87 #...and in the "past of the past"
88 for (j in 1:4)
89 {
90 if (i - 7*j >= 1)
91 days = c(days, i-7*j)
92 }
93 # TODO: exact computation instead of -364
94 # 364 = closest multiple of 7 to 365 - drift along the years... but not so many years so OK
95 i = i - 364
96 }
97
98 return ( days[1:min(limit,length(days))] )
99 }
100
101 #' getSerie
102 #'
103 #' Return a time-serie from its centered version + level
104 #'
105 #' @param data A list as returned by \code{getData}
106 #' @param index The index to return
107 #'
108 #' @export
109 getSerie = function(data, index)
110 data[[index]]$centered_serie + data[[index]]$level
111
112 #' getNoNA2
113 #'
114 #' Get indices in data of no-NA series followed by no-NA, within [first,last] range.
115 #'
116 #' @param data Object of class Data
117 #' @param first First index (included)
118 #' @param last Last index (included)
119 #'
120 #' @export
121 getNoNA2 = function(data, first, last)
122 {
123 (first:last)[ sapply(first:last, function(i)
124 !any( is.na(data$getCenteredSerie(i)) | is.na(data$getCenteredSerie(i+1)) )
125 ) ]
126 }