X-Git-Url: https://git.auder.net/?p=talweg.git;a=blobdiff_plain;f=pkg%2FR%2FF_Neighbors2.R;h=fb63e4087f1b2aa4b426712d140132a2f2e83193;hp=7267661eaeda8201810cef5fc3c6a2ab903ca57c;hb=5e838b3e17465c376ca075b766cf2543c82e9864;hpb=9db234c56c330bb3f652718c5ee1eb16bc1f6fc7 diff --git a/pkg/R/F_Neighbors2.R b/pkg/R/F_Neighbors2.R index 7267661..fb63e40 100644 --- a/pkg/R/F_Neighbors2.R +++ b/pkg/R/F_Neighbors2.R @@ -9,6 +9,15 @@ Neighbors2Forecaster = R6::R6Class("Neighbors2Forecaster", inherit = Forecaster, public = list( + predictSerie = function(data, today, memory, horizon, ...) + { + # Parameters (potentially) computed during shape prediction stage + predicted_shape = self$predictShape(data, today, memory, horizon, ...) +# predicted_delta = private$.pjump(data,today,memory,horizon,private$.params,...) + # Predicted shape is aligned it on the end of current day + jump +# predicted_shape+tail(data$getSerie(today),1)-predicted_shape[1]+predicted_delta + predicted_shape + }, predictShape = function(data, today, memory, horizon, ...) { # (re)initialize computed parameters @@ -22,43 +31,73 @@ Neighbors2Forecaster = R6::R6Class("Neighbors2Forecaster", fdays = getNoNA2(data, max(today-memory,1), today-1) # Get optional args + simtype = ifelse(hasArg("simtype"), list(...)$simtype, "mix") #or "endo", or "exo" kernel = ifelse(hasArg("kernel"), list(...)$kernel, "Gauss") #or "Epan" if (hasArg(h_window)) { return ( private$.predictShapeAux(data, - fdays, today, horizon, list(...)$h_window, kernel, TRUE) ) + fdays, today, horizon, list(...)$h_window, kernel, simtype, TRUE) ) } # Indices of similar days for cross-validation; TODO: 45 = magic number sdays = getSimilarDaysIndices(today, limit=45, same_season=FALSE) + cv_days = intersect(fdays,sdays) + # Limit to 20 most recent matching days (TODO: 20 == magic number) + cv_days = sort(cv_days,decreasing=TRUE)[1:min(20,length(cv_days))] + # Function to optimize h : h |--> sum of prediction errors on last 45 "similar" days - errorOnLastNdays = function(h, kernel) + errorOnLastNdays = function(h, kernel, simtype) { error = 0 nb_jours = 0 - for (day in intersect(fdays,sdays)) + for (i in seq_along(cv_days)) { # mix_strategy is never used here (simtype != "mix"), therefore left blank - prediction = private$.predictShapeAux(data,fdays,day,horizon,h,kernel,FALSE) + prediction = private$.predictShapeAux(data, + fdays, cv_days[i], horizon, h, kernel, simtype, FALSE) if (!is.na(prediction[1])) { nb_jours = nb_jours + 1 error = error + - mean((data$getSerie(i+1)[1:horizon] - prediction)^2) + mean((data$getSerie(cv_days[i]+1)[1:horizon] - prediction)^2) } } return (error / nb_jours) } - # h :: only for endo in this variation - h_best = optimize(errorOnLastNdays, c(0,7), kernel=kernel)$minimum - return (private$.predictShapeAux(data,fdays,today,horizon,h_best,kernel,TRUE)) + if (simtype != "endo") + { + h_best_exo = optimize( + errorOnLastNdays, c(0,10), kernel=kernel, simtype="exo")$minimum + } + if (simtype != "exo") + { + h_best_endo = optimize( + errorOnLastNdays, c(0,10), kernel=kernel, simtype="endo")$minimum + } + + if (simtype == "endo") + { + return (private$.predictShapeAux(data, + fdays, today, horizon, h_best_endo, kernel, "endo", TRUE)) + } + if (simtype == "exo") + { + return (private$.predictShapeAux(data, + fdays, today, horizon, h_best_exo, kernel, "exo", TRUE)) + } + if (simtype == "mix") + { + h_best_mix = c(h_best_endo,h_best_exo) + return(private$.predictShapeAux(data, + fdays, today, horizon, h_best_mix, kernel, "mix", TRUE)) + } } ), private = list( # Precondition: "today" is full (no NAs) - .predictShapeAux = function(data, fdays, today, horizon, h, kernel, final_call) + .predictShapeAux = function(data, fdays, today, horizon, h, kernel, simtype, final_call) { fdays = fdays[ fdays < today ] # TODO: 3 = magic number @@ -69,7 +108,7 @@ Neighbors2Forecaster = R6::R6Class("Neighbors2Forecaster", sdays = getSimilarDaysIndices(today, limit=45, same_season=TRUE, data) indices = intersect(fdays,sdays) levelToday = data$getLevel(today) - distances = sapply(seq_along(indices), function(i) abs(data$getLevel(i)-levelToday)) + distances = sapply(indices, function(i) abs(data$getLevel(i)-levelToday)) same_pollution = (distances <= 2) if (sum(same_pollution) < 3) #TODO: 3 == magic number { @@ -79,53 +118,79 @@ Neighbors2Forecaster = R6::R6Class("Neighbors2Forecaster", } indices = indices[same_pollution] - # Now OK: indices same season, same pollution level - # ........... - + if (simtype != "exo") + { + h_endo = ifelse(simtype=="mix", h[1], h) - # ENDO:: Distances from last observed day to days in the past - serieToday = data$getSerie(today) - distances2 = sapply(indices, function(i) { - delta = serieToday - data$getSerie(i) - distances2[i] = mean(delta^2) - }) + # Distances from last observed day to days in the past + serieToday = data$getSerie(today) + distances2 = sapply(indices, function(i) { + delta = serieToday - data$getSerie(i) + mean(delta^2) + }) - sd_dist = sd(distances2) - if (sd_dist < .Machine$double.eps) - { + sd_dist = sd(distances2) + if (sd_dist < .Machine$double.eps) + { # warning("All computed distances are very close: stdev too small") - sd_dist = 1 #mostly for tests... FIXME: + sd_dist = 1 #mostly for tests... FIXME: + } + simils_endo = + if (kernel=="Gauss") + exp(-distances2/(sd_dist*h_endo^2)) + else + { + # Epanechnikov + u = 1 - distances2/(sd_dist*h_endo^2) + u[abs(u)>1] = 0. + u + } } - simils_endo = - if (kernel=="Gauss") - exp(-distances2/(sd_dist*h_endo^2)) - else + + if (simtype != "endo") + { + h_exo = ifelse(simtype=="mix", h[2], h) + + M = matrix( nrow=1+length(indices), ncol=1+length(data$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])) ) + + sigma = cov(M) #NOTE: robust covariance is way too slow +# sigma_inv = solve(sigma) #TODO: use pseudo-inverse if needed? + sigma_inv = MASS::ginv(sigma) +#if (final_call) browser() + # Distances from last observed day to days in the past + distances2 = sapply(seq_along(indices), function(i) { + delta = M[1,] - M[i+1,] + delta %*% sigma_inv %*% delta + }) + + sd_dist = sd(distances2) + if (sd_dist < .25 * sqrt(.Machine$double.eps)) { - # Epanechnikov - u = 1 - distances2/(sd_dist*h_endo^2) - u[abs(u)>1] = 0. - u +# warning("All computed distances are very close: stdev too small") + sd_dist = 1 #mostly for tests... FIXME: } + simils_exo = + if (kernel=="Gauss") + exp(-distances2/(sd_dist*h_exo^2)) + else + { + # Epanechnikov + u = 1 - distances2/(sd_dist*h_exo^2) + u[abs(u)>1] = 0. + u + } + } -# # EXOGENS: distances computations are enough -# # TODO: search among similar concentrations....... at this stage ?! -# M = matrix( nrow=1+length(fdays), ncol=1+length(data$getExo(today)) ) -# M[1,] = c( data$getLevel(today), as.double(data$getExo(today)) ) -# for (i in seq_along(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 -# sigma_inv = solve(sigma) #TODO: use pseudo-inverse if needed? -# -# # Distances from last observed day to days in the past -# distances2 = rep(NA, nrow(M)-1) -# for (i in 2:nrow(M)) -# { -# delta = M[1,] - M[i,] -# distances2[i-1] = delta %*% sigma_inv %*% delta -# } - - similarities = simils_endo + similarities = + if (simtype == "exo") + simils_exo + else if (simtype == "endo") + simils_endo + else #mix + simils_endo * simils_exo prediction = rep(0, horizon) for (i in seq_along(indices)) @@ -135,8 +200,14 @@ Neighbors2Forecaster = R6::R6Class("Neighbors2Forecaster", if (final_call) { private$.params$weights <- similarities - private$.params$indices <- indices - private$.params$window <- h + private$.params$indices <- fdays + private$.params$window <- + if (simtype=="endo") + h_endo + else if (simtype=="exo") + h_exo + else #mix + c(h_endo,h_exo) } return (prediction)