No longer direct predict for Neighbors2: recollement comme Neighbors (better)
[talweg.git] / pkg / R / F_Neighbors2.R
index 787dd2b..69e69dc 100644 (file)
@@ -9,11 +9,6 @@ Neighbors2Forecaster = R6::R6Class("Neighbors2Forecaster",
        inherit = Forecaster,
 
        public = list(
-               predictSerie = function(data, today, memory, horizon, ...)
-               {
-                       # This method predict shape + level at the same time, all in next call
-                       self$predictShape(data, today, memory, horizon, ...)
-               },
                predictShape = function(data, today, memory, horizon, ...)
                {
                        # (re)initialize computed parameters
@@ -35,12 +30,8 @@ Neighbors2Forecaster = R6::R6Class("Neighbors2Forecaster",
                                        fdays, today, horizon, list(...)$h_window, kernel, simtype, TRUE) )
                        }
 
-                       # Indices of similar days for cross-validation; TODO: 45 = magic number
-                       sdays = getSimilarDaysIndices(today, data, limit=45, same_season=FALSE)
-
-                       cv_days = intersect(fdays,sdays)
-                       # Limit to 20 most recent matching days (TODO: 20 == magic number)
-                       cv_days = sort(cv_days,decreasing=TRUE)[1:min(20,length(cv_days))]
+                       # Indices of similar days for cross-validation; TODO: 20 = magic number
+                       cv_days = getSimilarDaysIndices(today, data, limit=20, same_season=FALSE, days_in=fdays)
 
                        # Function to optimize h : h |--> sum of prediction errors on last 45 "similar" days
                        errorOnLastNdays = function(h, kernel, simtype)
@@ -56,7 +47,7 @@ Neighbors2Forecaster = R6::R6Class("Neighbors2Forecaster",
                                        {
                                                nb_jours = nb_jours + 1
                                                error = error +
-                                                       mean((data$getSerie(cv_days[i]+1)[1:horizon] - prediction)^2)
+                                                       mean((data$getCenteredSerie(cv_days[i]+1)[1:horizon] - prediction)^2)
                                        }
                                }
                                return (error / nb_jours)
@@ -95,36 +86,35 @@ Neighbors2Forecaster = R6::R6Class("Neighbors2Forecaster",
                # Precondition: "today" is full (no NAs)
                .predictShapeAux = function(data, fdays, today, horizon, h, kernel, simtype, final_call)
                {
-                       fdays = fdays[ fdays < today ]
+                       fdays_cut = fdays[ fdays < today ]
                        # TODO: 3 = magic number
-                       if (length(fdays) < 3)
+                       if (length(fdays_cut) < 3)
                                return (NA)
 
-                       # Neighbors: days in "same season"
-                       sdays = getSimilarDaysIndices(today, data, limit=45, same_season=TRUE)
-                       indices = intersect(fdays,sdays)
-                       if (length(indices) <= 1)
+                       # Neighbors: days in "same season"; TODO: 60 == magic number...
+                       fdays = getSimilarDaysIndices(today, data, limit=60, same_season=TRUE, days_in=fdays_cut)
+                       if (length(fdays) <= 1)
                                return (NA)
                        levelToday = data$getLevel(today)
-                       distances = sapply(indices, function(i) abs(data$getLevel(i)-levelToday))
-                       # 2 and 5 below == magic numbers (determined by Bruno & Michel)
-                       same_pollution = (distances <= 2)
-                       if (sum(same_pollution) == 0)
+                       distances = sapply(fdays, function(i) abs(data$getLevel(i)-levelToday))
+                       dist_thresh = 1
+                       repeat
                        {
-                               same_pollution = (distances <= 5)
-                               if (sum(same_pollution) == 0)
-                                       return (NA)
+                               same_pollution = (distances <= dist_thresh)
+                               if (sum(same_pollution) >= 2) #will eventually happen
+                                       break
+                               dist_thresh = dist_thresh + 1
                        }
-                       indices = indices[same_pollution]
-                       if (length(indices) == 1)
+                       fdays = fdays[same_pollution]
+                       if (length(fdays) == 1)
                        {
                                if (final_call)
                                {
                                        private$.params$weights <- 1
-                                       private$.params$indices <- indices
+                                       private$.params$indices <- fdays
                                        private$.params$window <- 1
                                }
-                               return ( data$getSerie(indices[1])[1:horizon] ) #what else?!
+                               return ( data$getSerie(fdays[1])[1:horizon] ) #what else?!
                        }
 
                        if (simtype != "exo")
@@ -133,7 +123,7 @@ Neighbors2Forecaster = R6::R6Class("Neighbors2Forecaster",
 
                                # Distances from last observed day to days in the past
                                serieToday = data$getSerie(today)
-                               distances2 = sapply(indices, function(i) {
+                               distances2 = sapply(fdays, function(i) {
                                        delta = serieToday - data$getSerie(i)
                                        mean(delta^2)
                                })
@@ -160,21 +150,21 @@ Neighbors2Forecaster = R6::R6Class("Neighbors2Forecaster",
                        {
                                h_exo = ifelse(simtype=="mix", h[2], h)
 
-                               M = matrix( nrow=1+length(indices), ncol=1+length(data$getExo(today)) )
+                               M = matrix( nrow=1+length(fdays), ncol=1+length(data$getExo(today)) )
                                M[1,] = c( data$getLevel(today), as.double(data$getExo(today)) )
-                               for (i in seq_along(indices))
-                                       M[i+1,] = c( data$getLevel(indices[i]), as.double(data$getExo(indices[i])) )
+                               for (i in seq_along(fdays))
+                                       M[i+1,] = c( data$getLevel(fdays[i]), as.double(data$getExo(fdays[i])) )
 
                                sigma = cov(M) #NOTE: robust covariance is way too slow
                                # TODO: 10 == magic number; more robust way == det, or always ginv()
                                sigma_inv =
-                                       if (length(indices) > 10)
+                                       if (length(fdays) > 10)
                                                solve(sigma)
                                        else
                                                MASS::ginv(sigma)
 
                                # Distances from last observed day to days in the past
-                               distances2 = sapply(seq_along(indices), function(i) {
+                               distances2 = sapply(seq_along(fdays), function(i) {
                                        delta = M[1,] - M[i+1,]
                                        delta %*% sigma_inv %*% delta
                                })
@@ -206,14 +196,14 @@ Neighbors2Forecaster = R6::R6Class("Neighbors2Forecaster",
                                        simils_endo * simils_exo
 
                        prediction = rep(0, horizon)
-                       for (i in seq_along(indices))
-                               prediction = prediction + similarities[i] * data$getSerie(indices[i]+1)[1:horizon]
+                       for (i in seq_along(fdays))
+                               prediction = prediction + similarities[i] * data$getCenteredSerie(fdays[i]+1)[1:horizon]
                        prediction = prediction / sum(similarities, na.rm=TRUE)
 
                        if (final_call)
                        {
                                private$.params$weights <- similarities
-                               private$.params$indices <- indices
+                               private$.params$indices <- fdays
                                private$.params$window <-
                                        if (simtype=="endo")
                                                h_endo