TODO: unit tests for simil days

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

#' Average Forecaster
#'
#' Pointwise average of all the series of the same day of week in the past.
#'
#' For example, if the current day (argument "today") is a tuesday, then all series
#' corresponding to wednesdays in the past (until the beginning or memory limit) are
#' averaged to provide a smooth prediction. This forecast will most of the time be wrong,
#' but will also look plausible enough.
#'
#' @docType class
#' @format R6 class, inherits Forecaster
#' @aliases F_Average
#'
AverageForecaster = R6::R6Class("AverageForecaster",
	inherit = Forecaster,

	public = list(
		predictShape = function(data, today, memory, horizon, ...)
		{
			avg = rep(0., horizon)
			first_day = max(1, today-memory)
			index = today-7 + 1
			nb_no_na_series = 0
			repeat
			{
				{
					serie_on_horizon = data$getCenteredSerie(index)[1:horizon]
					index = index - 7
				};
				if (!any(is.na(serie_on_horizon)))
				{
					avg = avg + serie_on_horizon
					nb_no_na_series = nb_no_na_series + 1
				};
				if (index < first_day)
					break
			}
			avg / nb_no_na_series
		}
	)
)