3 #' Transform a (potential) date index into an integer (relative to data beginning).
5 #' @param index Date (or integer) index
6 #' @param data Object of class Data, output of \code{getData()}
9 dateIndexToInteger = function(index, data)
11 # Works on integers too: trust input
12 if (is.numeric(index))
13 index = as.integer(index)
14 if (is.integer(index))
17 if (inherits(index, "Date") || is.character(index))
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())
26 stop("Date outside data range")
28 stop("Unrecognized index format")
33 #' Transform an integer index (relative to data beginning) into a date index.
35 #' @inheritParams dateIndexToInteger
38 integerIndexToDate = function(index, data)
40 # Works on dates too: trust input
41 if (is.character(index))
42 index = as.Date(index)
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$getTime(index)[1] )
54 #' getSimilarDaysIndices
56 #' Find similar days indices in the past; at least same type of day in the week:
57 #' monday=tuesday=wednesday=thursday != friday != saturday != sunday.
59 #' @param index Day index (numeric or date)
60 #' @param data Reference dataset, object output of \code{getData}
61 #' @param limit Maximum number of indices to return
62 #' @param same_season Should the indices correspond to day in same season?
63 #' @param days_in Optional set to intersect with results (NULL to discard)
66 getSimilarDaysIndices = function(index, data, limit, same_season, days_in=NULL)
68 index = dateIndexToInteger(index, data)
70 # Look for similar days (optionally in same season)
72 dt_ref = as.POSIXlt(data$getTime(index)[1]) #first date-time of current day
73 day_ref = dt_ref$wday #1=monday, ..., 6=saturday, 0=sunday
74 month_ref = as.POSIXlt(data$getTime(index)[1])$mon+1 #month in 1...12
76 while (i >= 1 && length(days) < limit)
78 dt = as.POSIXlt(data$getTime(i)[1])
79 if ((is.null(days_in) || i %in% days_in) && .isSameDay(dt$wday, day_ref))
81 if (!same_season || .isSameSeason(dt$mon+1, month_ref))
91 # Check if two months fall in the same "season" (defined by estimated pollution rate).
93 # @param month Month index to test
94 # @param month_ref Month to compare to
96 .isSameSeason = function(month, month_ref)
98 if (month_ref %in% c(11,12,1,2)) #~= mid-polluted
99 return (month %in% c(11,12,1,2))
100 if (month_ref %in% c(3,4,9,10)) #~= high-polluted
101 return (month %in% c(3,4,9,10))
102 return (month %in% c(5,6,7,8)) #~= non polluted
107 # Monday=Tuesday=Wednesday=Thursday ; Friday, Saturday, Sunday: specials.
109 # @param day Day index to test
110 # @param day_ref Day index to compare to
112 .isSameDay = function(day, day_ref)
114 if (day_ref %in% 1:4)
115 return (day %in% 1:4)
116 return (day == day_ref)
121 # Get indices in data of no-NA series followed by no-NA, within [first,last] range.
123 # @inheritParams dateIndexToInteger
124 # @param first First index (included)
125 # @param last Last index (included)
127 .getNoNA2 = function(data, first, last)
129 (first:last)[ sapply(first:last, function(i)
130 !any( is.na(data$getCenteredSerie(i)) | is.na(data$getCenteredSerie(i+1)) )