R/aggreg_wam.R

In GeoFIS: Spatial Data Processing for Decision Making

################################################################################
#
# GeoFIS R package
#
# Copyright (C) 2021 INRAE
#
# Authors:
# 	Jean-luc Lablée - INRAE
# 	Serge Guillaume - INRAE
#
# License: CeCILL v2.1
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#' @title Class "AggregWam"
#' @name AggregWam
#' @docType class
#' @description The WAM aggregation operator to be used in [Fusion]
#'
#' @slot weights [numeric] vector, The weights of the WAM aggregation operator (the sum of the weights must be equal to 1 without negative values)
#'
#' @seealso {
#' [NewAggregWam]
#'
#' [Aggregation using numerical operators](https://www.geofis.org/en/documentation-en/data-fusion/#numerical-operators)
#' }
#'
setClass("AggregWam", slots = c(weights = "numeric"))

#' @importFrom methods callNextMethod
setMethod("initialize", "AggregWam", function(.Object, ...) {
  .Object <- callNextMethod()
  .CheckAggregWeights(.Object@weights)
  return(.Object)
})

#' @title Create object of class "AggregWam"
#' @name NewAggregWam
#' @description Function to create an aggregation operator of class [AggregWam] to be used in [Fusion]
#'
#' @param weights [numeric] vector, The weights of the WAM aggregation operator (the sum of the weights must be equal to 1 without negative values)
#'
#' @seealso [Aggregation using numerical operators](https://www.geofis.org/en/documentation-en/data-fusion/#numerical-operators)
#'
#' @export
NewAggregWam <- function(weights) {
  return(new("AggregWam", weights = weights))
}

setMethod(f = ".CheckAggreg", signature = c("AggregWam", "integer"), definition = function(aggreg, aggregate_length) {
  if (length(aggreg@weights) != aggregate_length) {
    stop("the WAM weigths must have the same length as the aggregate nodes")
  }
})

.ComputeWam <- function(x, weights) {
  return(sum(x * weights))
}

#' @importFrom data.tree Aggregate
setMethod(f = "Aggreg", signature = "AggregWam", definition = function(object, node, attribute) {
  return(Aggregate(node, attribute, aggFun = function(x) .ComputeWam(x, object@weights)))
})

toString.AggregWam <- function(x, ...) {
  return(sprintf("wam(%s)", paste(x@weights, collapse = ", ")))
}