X-Git-Url: https://git.auder.net/?a=blobdiff_plain;f=pkg%2FR%2FF_Neighbors.R;h=02536ebf164c9634c6bb7a6f23eeb3cf27fbbea9;hb=638f27f4296727aff62b56643beb9f42aa5b57ef;hp=ea18bb6bbda5220ce975ba7c06682006a6a6d3cb;hpb=d2ab47a744d8fb29c03a76a7ca2368dae53f9a57;p=talweg.git diff --git a/pkg/R/F_Neighbors.R b/pkg/R/F_Neighbors.R index ea18bb6..02536eb 100644 --- a/pkg/R/F_Neighbors.R +++ b/pkg/R/F_Neighbors.R @@ -45,27 +45,32 @@ NeighborsForecaster = R6::R6Class("NeighborsForecaster", private$.params <- list("weights"=NA, "indices"=NA, "window"=NA) # Do not forecast on days with NAs (TODO: softer condition...) - if (any(is.na(data$getSerie(today-1))) - || any(is.na(data$getSerie(today)[1:(predict_from-1)]))) + if (any(is.na(data$getSerie(today-1))) || + (predict_from>=2 && any(is.na(data$getSerie(today)[1:(predict_from-1)])))) { return (NA) } - # Determine indices of no-NAs days followed by no-NAs tomorrows - fdays = .getNoNA2(data, max(today-memory,1), today-2) - # Get optional args local = ifelse(hasArg("local"), list(...)$local, TRUE) #same level + season? simtype = ifelse(hasArg("simtype"), list(...)$simtype, "none") #or "endo", or "exo" + opera = ifelse(hasArg("opera"), list(...)$opera, FALSE) #operational mode? + + # Determine indices of no-NAs days preceded by no-NAs yerstedays + tdays = .getNoNA2(data, max(today-memory,2), ifelse(opera,today-1,data$getSize())) + if (!opera) + tdays = setdiff(tdays, today) #always exclude current day + + # Shortcut if window is known if (hasArg("window")) { - return ( private$.predictShapeAux(data, - fdays, today, predict_from, horizon, local, list(...)$window, simtype, TRUE) ) + return ( private$.predictShapeAux(data, tdays, today, predict_from, horizon, + local, list(...)$window, simtype, opera, TRUE) ) } # Indices of similar days for cross-validation; TODO: 20 = magic number cv_days = getSimilarDaysIndices(today, data, limit=20, same_season=FALSE, - days_in=fdays) + days_in=tdays, operational=opera) # Optimize h : h |--> sum of prediction errors on last N "similar" days errorOnLastNdays = function(window, simtype) @@ -75,13 +80,13 @@ NeighborsForecaster = R6::R6Class("NeighborsForecaster", for (i in seq_along(cv_days)) { # mix_strategy is never used here (simtype != "mix"), therefore left blank - prediction = private$.predictShapeAux(data, fdays, cv_days[i], predict_from, - horizon, local, window, simtype, FALSE) + prediction = private$.predictShapeAux(data, tdays, cv_days[i], predict_from, + horizon, local, window, simtype, opera, FALSE) if (!is.na(prediction[1])) { nb_jours = nb_jours + 1 error = error + - mean((data$getSerie(cv_days[i]+1)[predict_from:horizon] - prediction)^2) + mean((data$getSerie(cv_days[i])[predict_from:horizon] - prediction)^2) } } return (error / nb_jours) @@ -109,53 +114,60 @@ NeighborsForecaster = R6::R6Class("NeighborsForecaster", else #none: value doesn't matter 1 - return( private$.predictShapeAux(data, fdays, today, predict_from, horizon, local, - best_window, simtype, TRUE) ) + return( private$.predictShapeAux(data, tdays, today, predict_from, horizon, local, + best_window, simtype, opera, TRUE) ) } ), private = list( - # Precondition: "today" is full (no NAs) - .predictShapeAux = function(data, fdays, today, predict_from, horizon, local, window, - simtype, final_call) + # Precondition: "yersteday until predict_from-1" is full (no NAs) + .predictShapeAux = function(data, tdays, today, predict_from, horizon, local, window, + simtype, opera, final_call) { - fdays_cut = fdays[ fdays < today ] - if (length(fdays_cut) <= 1) + tdays_cut = tdays[ tdays != today ] + if (length(tdays_cut) == 0) return (NA) if (local) { # TODO: 60 == magic number - fdays = getSimilarDaysIndices(today, data, limit=60, same_season=TRUE, - days_in=fdays_cut) - if (length(fdays) <= 1) - return (NA) - # TODO: 10, 12 == magic numbers - fdays = .getConstrainedNeighbs(today,data,fdays,min_neighbs=10,max_neighbs=12) - if (length(fdays) == 1) + tdays = getSimilarDaysIndices(today, data, limit=60, same_season=TRUE, + days_in=tdays_cut, operational=opera) +# if (length(tdays) <= 1) +# return (NA) + # TODO: 10 == magic number + tdays = .getConstrainedNeighbs(today, data, tdays, min_neighbs=10) + if (length(tdays) == 1) { if (final_call) { private$.params$weights <- 1 - private$.params$indices <- fdays + private$.params$indices <- tdays private$.params$window <- 1 } - return ( data$getSerie(fdays[1]+1)[predict_from:horizon] ) + return ( data$getSerie(tdays[1])[predict_from:horizon] ) } } else - fdays = fdays_cut #no conditioning + tdays = tdays_cut #no conditioning if (simtype == "endo" || simtype == "mix") { # Compute endogen similarities using given window window_endo = ifelse(simtype=="mix", window[1], window) - # Distances from last observed day to days in the past - lastSerie = c( data$getSerie(today-1), data$getSerie(today)[1:(predict_from-1)] ) - distances2 = sapply(fdays, function(i) { - delta = lastSerie - c(data$getSerie(i),data$getSerie(i+1)[1:(predict_from-1)]) - sqrt(mean(delta^2)) - }) + # Distances from last observed day to selected days in the past + distances2 <- .computeDistsEndo(data, today, tdays, predict_from) + + if (local) + { + max_neighbs = 12 #TODO: 12 = arbitrary number + if (length(distances2) > max_neighbs) + { + ordering <- order(distances2) + tdays <- tdays[ ordering[1:max_neighbs] ] + distances2 <- distances2[ ordering[1:max_neighbs] ] + } + } simils_endo <- .computeSimils(distances2, window_endo) } @@ -165,24 +177,7 @@ NeighborsForecaster = R6::R6Class("NeighborsForecaster", # Compute exogen similarities using given window window_exo = ifelse(simtype=="mix", window[2], window) - M = matrix( ncol=1+length(fdays), nrow=1+length(data$getExo(1)) ) - M[,1] = c( data$getLevelHat(today), as.double(data$getExoHat(today)) ) - for (i in seq_along(fdays)) - M[,i+1] = c( data$getLevel(fdays[i]), as.double(data$getExo(fdays[i])) ) - - sigma = cov(t(M)) #NOTE: robust covariance is way too slow - # TODO: 10 == magic number; more robust way == det, or always ginv() - sigma_inv = - if (length(fdays) > 10) - solve(sigma) - else - MASS::ginv(sigma) - - # Distances from last observed day to days in the past - distances2 = sapply(seq_along(fdays), function(i) { - delta = M[,1] - M[,i+1] - delta %*% sigma_inv %*% delta - }) + distances2 <- .computeDistsExo(data, today, tdays) simils_exo <- .computeSimils(distances2, window_exo) } @@ -195,20 +190,20 @@ NeighborsForecaster = R6::R6Class("NeighborsForecaster", else if (simtype == "mix") simils_endo * simils_exo else #none - rep(1, length(fdays)) + rep(1, length(tdays)) similarities = similarities / sum(similarities) prediction = rep(0, horizon-predict_from+1) - for (i in seq_along(fdays)) + for (i in seq_along(tdays)) { prediction = prediction + - similarities[i] * data$getSerie(fdays[i]+1)[predict_from:horizon] + similarities[i] * data$getSerie(tdays[i])[predict_from:horizon] } if (final_call) { private$.params$weights <- similarities - private$.params$indices <- fdays + private$.params$indices <- tdays private$.params$window <- if (simtype=="endo") window_endo @@ -231,20 +226,21 @@ NeighborsForecaster = R6::R6Class("NeighborsForecaster", # # @param today Index of current day # @param data Object of class Data -# @param fdays Current set of "first days" (no-NA pairs) +# @param tdays Current set of "second days" (no-NA pairs) # @param min_neighbs Minimum number of points in a neighborhood # @param max_neighbs Maximum number of points in a neighborhood # -.getConstrainedNeighbs = function(today, data, fdays, min_neighbs=10, max_neighbs=12) +.getConstrainedNeighbs = function(today, data, tdays, min_neighbs=10) { levelToday = data$getLevelHat(today) - levelYersteday = data$getLevel(today-1) - distances = sapply(fdays, function(i) { - sqrt((data$getLevel(i)-levelYersteday)^2 + (data$getLevel(i+1)-levelToday)^2) +# levelYersteday = data$getLevel(today-1) + distances = sapply(tdays, function(i) { +# sqrt((data$getLevel(i-1)-levelYersteday)^2 + (data$getLevel(i)-levelToday)^2) + abs(data$getLevel(i)-levelToday) }) #TODO: 1, +1, +3 : magic numbers dist_thresh = 1 - min_neighbs = min(min_neighbs,length(fdays)) + min_neighbs = min(min_neighbs,length(tdays)) repeat { same_pollution = (distances <= dist_thresh) @@ -253,14 +249,14 @@ NeighborsForecaster = R6::R6Class("NeighborsForecaster", break dist_thresh = dist_thresh + ifelse(dist_thresh>1,3,1) } - fdays = fdays[same_pollution] - max_neighbs = 12 - if (nb_neighbs > max_neighbs) - { - # Keep only max_neighbs closest neighbors - fdays = fdays[ order(distances[same_pollution])[1:max_neighbs] ] - } - fdays + tdays = tdays[same_pollution] +# max_neighbs = 12 +# if (nb_neighbs > max_neighbs) +# { +# # Keep only max_neighbs closest neighbors +# tdays = tdays[ order(distances[same_pollution])[1:max_neighbs] ] +# } + tdays } # compute similarities @@ -280,3 +276,36 @@ NeighborsForecaster = R6::R6Class("NeighborsForecaster", } exp(-distances2/(sd_dist*window^2)) } + +.computeDistsEndo <- function(data, today, tdays, predict_from) +{ + lastSerie = c( data$getSerie(today-1), + data$getSerie(today)[if (predict_from>=2) 1:(predict_from-1) else c()] ) + sapply(tdays, function(i) { + delta = lastSerie - c(data$getSerie(i-1), + data$getSerie(i)[if (predict_from>=2) 1:(predict_from-1) else c()]) + sqrt(mean(delta^2)) + }) +} + +.computeDistsExo <- function(data, today, tdays) +{ + M = matrix( ncol=1+length(tdays), nrow=1+length(data$getExo(1)) ) + M[,1] = c( data$getLevelHat(today), as.double(data$getExoHat(today)) ) + for (i in seq_along(tdays)) + M[,i+1] = c( data$getLevel(tdays[i]), as.double(data$getExo(tdays[i])) ) + + sigma = cov(t(M)) #NOTE: robust covariance is way too slow + # TODO: 10 == magic number; more robust way == det, or always ginv() + sigma_inv = + if (length(tdays) > 10) + solve(sigma) + else + MASS::ginv(sigma) + + # Distances from last observed day to days in the past + sapply(seq_along(tdays), function(i) { + delta = M[,1] - M[,i+1] + delta %*% sigma_inv %*% delta + }) +}