R/D_Neighbors.R

   1 #' Obtain delta forecast by the Neighbors method
   2 #'
   3 #' @inheritParams getForecast
   4 #' @inheritParams getZeroDeltaForecast
   5 getNeighborsDeltaForecast = function(data, today, memory, horizon, shape_params, ...)
   6 {
   7     first_day = max(1, today-memory)
   8     filter = shape_params$indices >= first_day
   9     indices = shape_params$indices[filter]
  10     weights = shape_params$weights[filter]
  11     if (any(is.na(weights) | is.na(indices)))
  12         return (NA)
  13
  14     gaps = sapply(indices, function(i) {
  15         data$getSerie(i+1)[1] - tail(data$getSerie(i), 1)
  16     })
  17
  18     scal_product = weights * gaps
  19     norm_fact = sum( weights[!is.na(scal_product)] )
  20     sum(scal_product, na.rm=TRUE) / norm_fact
  21 }