#' Compute error
#'
-#' Obtain the errors between forecast and data
+#' Compute the errors between forecasted and measured series.
#'
-#' @param data Dataset, object of class \code{Data} output of \code{getData}
-#' @param pred Forecast object, class \code{Forecast} output of \code{computeForecast}
+#' @param data Object of class \code{Data} output of \code{getData}
+#' @param pred Object of class \code{Forecast} output of \code{computeForecast}
#' @param horizon Horizon where to compute the error
#' (<= horizon used in \code{computeForecast})
#'
-#' @return A list (abs,MAPE) of lists (day,indices)
+#' @return A list (abs,MAPE) of lists (day,indices). The "indices" slots contain series
+#' of size L where L is the number of predicted days; i-th value is the averaged error
+#' (absolute or MAPE) on day i. The "day" slots contain curves of errors, for each time
+#' step, averaged on the L forecasting days.
#'
#' @export
computeError = function(data, pred, horizon=data$getStdHorizon())