From: Benjamin Auder Date: Wed, 16 Jun 2021 13:31:10 +0000 (+0200) Subject: Update in progress - unfinished X-Git-Url: https://git.auder.net/variants/current/doc/css/img/pieces/%7B%7B?a=commitdiff_plain;h=43a6578d444f388d72755e74c7eed74f3af638ec;p=agghoo.git Update in progress - unfinished --- diff --git a/.gitignore b/.gitignore index 82f0c3a..74e855c 100644 --- a/.gitignore +++ b/.gitignore @@ -1 +1,2 @@ /data/ +.RData diff --git a/R/R6_AgghooCV.R b/R/R6_AgghooCV.R index 81ddbe1..ed9aa5c 100644 --- a/R/R6_AgghooCV.R +++ b/R/R6_AgghooCV.R @@ -25,11 +25,11 @@ AgghooCV <- R6::R6Class("AgghooCV", private$loss <- loss }, #' @description Fit an agghoo model. - #' @param CV List describing cross-validation to run. Slots: - #' - type: 'vfold' or 'MC' for Monte-Carlo (default: MC) - #' - V: number of runs (default: 10) + #' @param CV List describing cross-validation to run. Slots: \cr + #' - type: 'vfold' or 'MC' for Monte-Carlo (default: MC) \cr + #' - V: number of runs (default: 10) \cr #' - test_size: percentage of data in the test dataset, for MC - #' (irrelevant for V-fold). Default: 0.2. + #' (irrelevant for V-fold). Default: 0.2. \cr #' - shuffle: wether or not to shuffle data before V-fold. #' Irrelevant for Monte-Carlo; default: TRUE fit = function( diff --git a/R/agghoo.R b/R/agghoo.R index cac2cf1..c8765fc 100644 --- a/R/agghoo.R +++ b/R/agghoo.R @@ -1,6 +1,6 @@ #' agghoo #' -#' Run the agghoo procedure (or standard cross-validation). +#' Run the (core) agghoo procedure. #' Arguments specify the list of models, their parameters and the #' cross-validation settings, among others. #' @@ -34,6 +34,8 @@ #' a_cla$fit() #' pc <- a_cla$predict(iris[,-5] + rnorm(600, sd=0.1)) #' +#' @seealso Function \code{\link{compareTo}} +#' #' @references #' Guillaume Maillard, Sylvain Arlot, Matthieu Lerasle. "Aggregated hold-out". #' Journal of Machine Learning Research 22(20):1--55, 2021. diff --git a/R/compareTo.R b/R/compareTo.R new file mode 100644 index 0000000..aa3a4e8 --- /dev/null +++ b/R/compareTo.R @@ -0,0 +1,186 @@ +standardCV_core <- function(data, target, task = NULL, gmodel = NULL, params = NULL, + loss = NULL, CV = list(type = "MC", V = 10, test_size = 0.2, shuffle = TRUE) +) { + if (!is.null(task)) + task = match.arg(task, c("classification", "regression")) + if (is.character(gmodel)) + gmodel <- match.arg(gmodel, c("knn", "ppr", "rf", "tree")) + if (is.numeric(params) || is.character(params)) + params <- as.list(params) + if (is.null(task)) { + if (is.numeric(target)) + task = "regression" + else + task = "classification" + } + + if (is.null(loss)) { + loss <- function(y1, y2) { + if (task == "classification") { + if (is.null(dim(y1))) + mean(y1 != y2) + else { + if (!is.null(dim(y2))) + mean(rowSums(abs(y1 - y2))) + else { + y2 <- as.character(y2) + names <- colnames(y1) + positions <- list() + for (idx in seq_along(names)) + positions[[ names[idx] ]] <- idx + mean(vapply( + seq_along(y2), + function(idx) sum(abs(y1[idx,] - positions[[ y2[idx] ]])), + 0)) + } + } + } + else + mean(abs(y1 - y2)) + } + } + + n <- nrow(data) + shuffle_inds <- NULL + if (CV$type == "vfold" && CV$shuffle) + shuffle_inds <- sample(n, n) + get_testIndices <- function(v, shuffle_inds) { + if (CV$type == "vfold") { + first_index = round((v-1) * n / CV$V) + 1 + last_index = round(v * n / CV$V) + test_indices = first_index:last_index + if (!is.null(shuffle_inds)) + test_indices <- shuffle_inds[test_indices] + } + else + test_indices = sample(n, round(n * CV$test_size)) + test_indices + } + list_testinds <- list() + for (v in seq_len(CV$V)) + list_testinds[[v]] <- get_testIndices(v, shuffle_inds) + + gmodel <- agghoo::Model$new(data, target, task, gmodel, params) + best_error <- Inf + best_model <- NULL + for (p in seq_len(gmodel$nmodels)) { + error <- 0 + for (v in seq_len(CV$V)) { + testIdx <- list_testinds[[v]] + dataHO <- data[-testIdx,] + testX <- data[testIdx,] + targetHO <- target[-testIdx] + testY <- target[testIdx] + if (!is.matrix(dataHO) && !is.data.frame(dataHO)) + dataHO <- as.matrix(dataHO) + if (!is.matrix(testX) && !is.data.frame(testX)) + testX <- as.matrix(testX) + model_pred <- gmodel$get(dataHO, targetHO, p) + prediction <- model_pred(testX) + error <- error + loss(prediction, testY) + } + if (error <= best_error) { + newModel <- list(model=model_pred, param=gmodel$getParam(p)) + if (error == best_error) + best_model[[length(best_model)+1]] <- newModel + else { + best_model <- list(newModel) + best_error <- error + } + } + } + best_model[[ sample(length(best_model), 1) ]] +} + +standardCV_run <- function( + dataTrain, dataTest, targetTrain, targetTest, verbose, CV, floss, ... +) { + s <- standardCV_core(dataTrain, targetTrain, ...) + if (verbose) + print(paste( "Parameter:", s$param )) + ps <- s$model(test) + err_s <- floss(ps, targetTest) + if (verbose) + print(paste("error CV:", err_s)) + invisible(c(errors, err_s)) +} + +agghoo_run <- function( + dataTrain, dataTest, targetTrain, targetTest, verbose, CV, floss, ... +) { + a <- agghoo(dataTrain, targetTrain, ...) + a$fit(CV) + if (verbose) { + print("Parameters:") + print(unlist(a$getParams())) + } + pa <- a$predict(dataTest) + err <- floss(pa, targetTest) + if (verbose) + print(paste("error agghoo:", err)) +} + +# ... arguments passed to agghoo or any other procedure +compareTo <- function( + data, target, rseed=-1, verbose=TRUE, floss=NULL, + CV = list(type = "MC", + V = 10, + test_size = 0.2, + shuffle = TRUE), + method_s=NULL, ... +) { + if (rseed >= 0) + set.seed(rseed) + n <- nrow(data) + test_indices <- sample( n, round(n / ifelse(n >= 500, 10, 5)) ) + trainData <- as.matrix(data[-test_indices,]) + trainTarget <- target[-test_indices] + testData <- as.matrix(data[test_indices,]) + testTarget <- target[test_indices] + + # Set error function to be used on model outputs (not in core method) + if (is.null(floss)) { + floss <- function(y1, y2) { + ifelse(task == "classification", mean(y1 != y2), mean(abs(y1 - y2))) + } + } + + # Run (and compare) all methods: + runOne <- function(o) { + o(dataTrain, dataTest, targetTrain, targetTest, verbose, CV, floss, ...) + } + if (is.list(method_s)) + errors <- sapply(method_s, runOne) + else if (is.function(method_s)) + errors <- runOne(method_s) + else + errors <- c() + invisible(errors) +} + +# Run compareTo N times in parallel +compareMulti <- function( + data, target, N = 100, nc = NA, + CV = list(type = "MC", + V = 10, + test_size = 0.2, + shuffle = TRUE), + method_s=NULL, ... +) { + if (is.na(nc)) + nc <- parallel::detectCores() + compareOne <- function(n) { + print(n) + compareTo(data, target, n, verbose=FALSE, CV, method_s, ...) + } + errors <- if (nc >= 2) { + require(parallel) + parallel::mclapply(1:N, compareOne, mc.cores = nc) + } else { + lapply(1:N, compareOne) + } + print("Errors:") + Reduce('+', errors) / N +} + +# TODO: unfinished ! diff --git a/man/AgghooCV.Rd b/man/AgghooCV.Rd index e37224b..75ce9db 100644 --- a/man/AgghooCV.Rd +++ b/man/AgghooCV.Rd @@ -7,13 +7,6 @@ Class encapsulating the methods to run to obtain the best predictor from the list of models (see 'Model' class). } -\section{Public fields}{ -\if{html}{\out{
}} -\describe{ -\item{\code{params}}{List of parameters of the V selected models} -} -\if{html}{\out{
}} -} \section{Methods}{ \subsection{Public methods}{ \itemize{ @@ -61,10 +54,10 @@ Fit an agghoo model. \subsection{Arguments}{ \if{html}{\out{
}} \describe{ -\item{\code{CV}}{List describing cross-validation to run. Slots: -- type: 'vfold' or 'MC' for Monte-Carlo (default: MC) -- V: number of runs (default: 10) -- test_size: percentage of data in the test dataset, for MC +\item{\code{CV}}{List describing cross-validation to run. Slots: \cr +- type: 'vfold' or 'MC' for Monte-Carlo (default: MC) \cr +- V: number of runs (default: 10) \cr +- test_size: percentage of data in the test dataset, for MC \cr (irrelevant for V-fold). Default: 0.2. - shuffle: wether or not to shuffle data before V-fold. Irrelevant for Monte-Carlo; default: TRUE}