prepare report on one full year (2015)
[talweg.git] / pkg / R / utils.R
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1#' dateIndexToInteger
2#'
3#' Transform a (potential) date index into an integer (relative to data beginning).
4#'
5#' @param index Date (or integer) index
6#' @param data Object of class Data, output of \code{getData()}
7#'
8#' @export
9dateIndexToInteger = 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),
20 error=function(e) stop("Unrecognized index format"))
21 #TODO: tz arg to difftime ?
22 integerIndex <- round( as.numeric(
23 difftime(indexAsDate, as.Date(data$getTime(1)[1])) ) ) + 1
24 if (integerIndex >= 1 && integerIndex <= data$getSize())
25 return (integerIndex)
26 stop("Date outside data range")
27 }
28 stop("Unrecognized index format")
29}
30
31#' integerIndexToDate
32#'
33#' Transform an integer index (relative to data beginning) into a date index.
34#'
35#' @inheritParams dateIndexToInteger
36#'
37#' @export
38integerIndexToDate = 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$getTime(index)[1] )
52}
53
54#' getSimilarDaysIndices
55#'
56#' Find similar days indices in the past; at least same type of day in the week:
57#' monday=tuesday=wednesday=thursday != friday != saturday != sunday.
58#'
59#' @param index Day index (numeric or date)
60#' @param data Reference dataset, object output of \code{getData}
61#' @param limit Maximum number of indices to return
62#' @param same_season Should the indices correspond to day in same season?
63#' @param days_in Optional set to intersect with results (NULL to discard)
64#'
65#' @export
66getSimilarDaysIndices = function(index, data, limit, same_season,
67 days_in=NULL, operational=TRUE)
68{
69 index = dateIndexToInteger(index, data)
70
71 # Look for similar days (optionally in same season)
72 days = c()
73 dt_ref = as.POSIXlt(data$getTime(index)[1]) #first date-time of current day
74 day_ref = dt_ref$wday #1=monday, ..., 6=saturday, 0=sunday
75 month_ref = as.POSIXlt(data$getTime(index)[1])$mon+1 #month in 1...12
76 i = index - 1
77 if (!operational)
78 j = index + 1
79 while (length(days) < min( limit, ifelse(is.null(days_in),Inf,length(days_in)) ))
80 {
81 if (i < 1 && j > data$getSize())
82 break
83 if (i >= 1)
84 {
85 dt = as.POSIXlt(data$getTime(i)[1])
86 if ((is.null(days_in) || i %in% days_in) && .isSameDay(dt$wday, day_ref))
87 {
88 if (!same_season || .isSameSeason(dt$mon+1, month_ref))
89 days = c(days, i)
90 }
91 i = i - 1
92 }
93 if (!operational && j <= data$getSize())
94 {
95 dt = as.POSIXlt(data$getTime(j)[1])
96 if ((is.null(days_in) || j %in% days_in) && .isSameDay(dt$wday, day_ref))
97 {
98 if (!same_season || .isSameSeason(dt$mon+1, month_ref))
99 days = c(days, j)
100 }
101 j = j + 1
102 }
103 }
104 return ( days )
105}
106
107# isSameSeason
108#
109# Check if two months fall in the same "season" (defined by estimated pollution rate).
110#
111# @param month Month index to test
112# @param month_ref Month to compare to
113#
114.isSameSeason = function(month, month_ref)
115{
116# if (month_ref == 3) #TODO: same as Bruno (but weird)
117# return (month %in% c(2,3,4,9,10))
118 if (month_ref %in% c(11,12,1,2)) #~= mid-polluted
119 return (month %in% c(11,12,1,2))
120 if (month_ref %in% c(3,4,9,10)) #~= high-polluted
121 return (month %in% c(3,4,9,10))
122 return (month %in% c(5,6,7,8)) #~= non polluted
123}
124
125# isSameDay
126#
127# Monday=Tuesday=Wednesday=Thursday ; Friday, Saturday, Sunday: specials.
128#
129# @param day Day index to test
130# @param day_ref Day index to compare to
131#
132.isSameDay = function(day, day_ref)
133{
134 if (day_ref %in% 1:4)
135 return (day %in% 1:4)
136 return (day == day_ref)
137}
138
139# getNoNA2
140#
141# Get indices in data of no-NA series preceded by no-NA, within [first,last] range.
142#
143# @inheritParams dateIndexToInteger
144# @param first First index (included)
145# @param last Last index (included)
146#
147.getNoNA2 = function(data, first, last)
148{
149 (first:last)[ sapply(first:last, function(i)
150 !any( is.na(data$getSerie(i-1)) | is.na(data$getSerie(i)) )
151 ) ]
152}