[talweg.git] / pkg / R / utils.R

#' @title dateIndexToInteger
#'
#' @description Transform a (potential) date index into an integer (relative to data)
#'
#' @param index Date (or integer) index
#' @param data Object of class \code{Data}
#'
#' @export
dateIndexToInteger = function(index, data)
{
	index = index[1]
	if (is.numeric(index))
		index = as.integer(index)
	if (is.integer(index))
		return (index)
	if (inherits(index, "Date") || is.character(index))
	{
		tryCatch(indexAsDate <- as.Date(index), error=function(e) stop("Unrecognized index format"))
		#TODO: tz arg to difftime ?
		integerIndex <- round( as.numeric(
			difftime(indexAsDate, as.Date(data$getTime(1)[1])) ) ) + 1
		if (integerIndex >= 1 && integerIndex <= data$getSize())
		{
			#WARNING: if index>=2 && series start at date >0h, result must be shifted
			#Convention: if first date asked, return first matching index (i.e.: 1)
			shift = 0
			if (integerIndex >= 2)
			{
				date1 = as.POSIXlt(data$getTime(1)[1])
				date2 = as.POSIXlt(data$getTime(2)[1])
				shift = (date1$year==date2$year && date1$mon==date2$mon && date1$mday==date2$mday)
			}
			return (integerIndex + shift)
		}
		stop("Date outside data range")
	}
	stop("Unrecognized index format")
}

#' @title integerIndexToDate
#'
#' @description Transform an integer index to date index (relative to data)
#'
#' @param index Date (or integer) index
#' @param data Object of class \code{Data}
#'
#' @export
integerIndexToDate = function(index, data)
{
	index = index[1]
	if (is.numeric(index))
		index = as.integer(index)
	if (!is.integer(index))
		stop("'index' should be an integer")
	as.Date( data$getTime(index)[1] )
}

#' @title getSimilarDaysIndices
#'
#' @description Find similar days indices in the past
#'
#' @param index Day index (numeric or date)
#' @param limit Maximum number of indices to return
#' @param same_seaon Should the indices correspond to day in same season?
#'
#' @export
getSimilarDaysIndices = function(index, limit, same_season)
{
	index = dateIndexToInteger(index)

	#TODO: mardi similaire à lundi mercredi jeudi aussi ...etc
	if (!same_season)
	{
		#take all similar days in recent past
		nb_days = min( (index-1) %/% 7, limit)
		return ( rep(index,nb_days) - 7*seq_len(nb_days) )
	}

	#Look for similar days in similar season (+/- 30 days)
	days = c()
	i = index
	while (i >= 1 && length(days) < limit)
	{
		if (i < index)
		{
			days = c(days, i)
			#look in the "future of the past"
			for (j in 1:4)
				days = c(days, i+7*j)
		}
		#...and in the "past of the past"
		for (j in 1:4)
		{
			if (i - 7*j >= 1)
				days = c(days, i-7*j)
		}
		# TODO: exact computation instead of -364
		# 364 = closest multiple of 7 to 365 - drift along the years... but not so many years so OK
		i = i - 364
	}

	return ( days[1:min(limit,length(days))] )
}
Commit	Line	Data
3d69ff21 BA	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	{
09cf9c19	11	index = index[1]
3d69ff21 BA	12	if (is.numeric(index))
3d69ff21 BA	13	index = as.integer(index)
3d69ff21	14	if (is.integer(index))
09cf9c19 BA	15	return (index)
09cf9c19 BA	16	if (inherits(index, "Date") \|\| is.character(index))
3d69ff21	17	{
44a9990b	18	tryCatch(indexAsDate <- as.Date(index), error=function(e) stop("Unrecognized index format"))
3d69ff21	19	#TODO: tz arg to difftime ?
44a9990b BA	20	integerIndex <- round( as.numeric(
	21	difftime(indexAsDate, as.Date(data$getTime(1)[1])) ) ) + 1
	22	if (integerIndex >= 1 && integerIndex <= data$getSize())
09cf9c19	23	{
44a9990b BA	24	#WARNING: if index>=2 && series start at date >0h, result must be shifted
	25	#Convention: if first date asked, return first matching index (i.e.: 1)
	26	shift = 0
	27	if (integerIndex >= 2)
	28	{
	29	date1 = as.POSIXlt(data$getTime(1)[1])
	30	date2 = as.POSIXlt(data$getTime(2)[1])
	31	shift = (date1$year==date2$year && date1$mon==date2$mon && date1$mday==date2$mday)
	32	}
	33	return (integerIndex + shift)
09cf9c19	34	}
3d69ff21 BA	35	stop("Date outside data range")
	36	}
	37	stop("Unrecognized index format")
	38	}
	39
09cf9c19 BA	40	#' @title integerIndexToDate
	41	#'
	42	#' @description Transform an integer index to date index (relative to data)
	43	#'
	44	#' @param index Date (or integer) index
	45	#' @param data Object of class \code{Data}
	46	#'
	47	#' @export
	48	integerIndexToDate = function(index, data)
	49	{
	50	index = index[1]
	51	if (is.numeric(index))
	52	index = as.integer(index)
	53	if (!is.integer(index))
	54	stop("'index' should be an integer")
	55	as.Date( data$getTime(index)[1] )
	56	}
	57
3d69ff21 BA	58	#' @title getSimilarDaysIndices
	59	#'
	60	#' @description Find similar days indices in the past
	61	#'
	62	#' @param index Day index (numeric or date)
	63	#' @param limit Maximum number of indices to return
	64	#' @param same_seaon Should the indices correspond to day in same season?
	65	#'
	66	#' @export
	67	getSimilarDaysIndices = function(index, limit, same_season)
	68	{
	69	index = dateIndexToInteger(index)
	70
	71	#TODO: mardi similaire à lundi mercredi jeudi aussi ...etc
	72	if (!same_season)
	73	{
	74	#take all similar days in recent past
	75	nb_days = min( (index-1) %/% 7, limit)
	76	return ( rep(index,nb_days) - 7*seq_len(nb_days) )
	77	}
	78
	79	#Look for similar days in similar season (+/- 30 days)
	80	days = c()
	81	i = index
	82	while (i >= 1 && length(days) < limit)
	83	{
	84	if (i < index)
	85	{
	86	days = c(days, i)
	87	#look in the "future of the past"
	88	for (j in 1:4)
	89	days = c(days, i+7*j)
	90	}
	91	#...and in the "past of the past"
	92	for (j in 1:4)
	93	{
	94	if (i - 7*j >= 1)
	95	days = c(days, i-7*j)
	96	}
	97	# TODO: exact computation instead of -364
	98	# 364 = closest multiple of 7 to 365 - drift along the years... but not so many years so OK
	99	i = i - 364
	100	}
	101
	102	return ( days[1:min(limit,length(days))] )
	103	}