2020-04-03 08:03:26 +08:00

337 lines
14 KiB
R

require(xgboost)
context("basic functions")
data(agaricus.train, package='xgboost')
data(agaricus.test, package='xgboost')
train <- agaricus.train
test <- agaricus.test
set.seed(1994)
# disable some tests for Win32
windows_flag = .Platform$OS.type == "windows" &&
.Machine$sizeof.pointer != 8
solaris_flag = (Sys.info()['sysname'] == "SunOS")
test_that("train and predict binary classification", {
nrounds = 2
expect_output(
bst <- xgboost(data = train$data, label = train$label, max_depth = 2,
eta = 1, nthread = 2, nrounds = nrounds, objective = "binary:logistic")
, "train-error")
expect_equal(class(bst), "xgb.Booster")
expect_equal(bst$niter, nrounds)
expect_false(is.null(bst$evaluation_log))
expect_equal(nrow(bst$evaluation_log), nrounds)
expect_lt(bst$evaluation_log[, min(train_error)], 0.03)
pred <- predict(bst, test$data)
expect_length(pred, 1611)
pred1 <- predict(bst, train$data, ntreelimit = 1)
expect_length(pred1, 6513)
err_pred1 <- sum((pred1 > 0.5) != train$label)/length(train$label)
err_log <- bst$evaluation_log[1, train_error]
expect_lt(abs(err_pred1 - err_log), 10e-6)
})
test_that("dart prediction works", {
nrounds = 32
set.seed(1994)
d <- cbind(
x1 = rnorm(100),
x2 = rnorm(100),
x3 = rnorm(100))
y <- d[,"x1"] + d[,"x2"]^2 +
ifelse(d[,"x3"] > .5, d[,"x3"]^2, 2^d[,"x3"]) +
rnorm(100)
set.seed(1994)
booster_by_xgboost <- xgboost(data = d, label = y, max_depth = 2, booster = "dart",
rate_drop = 0.5, one_drop = TRUE,
eta = 1, nthread = 2, nrounds = nrounds, objective = "reg:squarederror")
pred_by_xgboost_0 <- predict(booster_by_xgboost, newdata = d, ntreelimit = 0)
pred_by_xgboost_1 <- predict(booster_by_xgboost, newdata = d, ntreelimit = nrounds)
expect_true(all(matrix(pred_by_xgboost_0, byrow=TRUE) == matrix(pred_by_xgboost_1, byrow=TRUE)))
pred_by_xgboost_2 <- predict(booster_by_xgboost, newdata = d, training = TRUE)
expect_false(all(matrix(pred_by_xgboost_0, byrow=TRUE) == matrix(pred_by_xgboost_2, byrow=TRUE)))
set.seed(1994)
dtrain <- xgb.DMatrix(data=d, info = list(label=y))
booster_by_train <- xgb.train( params = list(
booster = "dart",
max_depth = 2,
eta = 1,
rate_drop = 0.5,
one_drop = TRUE,
nthread = 1,
tree_method= "exact",
verbosity = 3,
objective = "reg:squarederror"
),
data = dtrain,
nrounds = nrounds
)
pred_by_train_0 <- predict(booster_by_train, newdata = dtrain, ntreelimit = 0)
pred_by_train_1 <- predict(booster_by_train, newdata = dtrain, ntreelimit = nrounds)
pred_by_train_2 <- predict(booster_by_train, newdata = dtrain, training = TRUE)
expect_true(all(matrix(pred_by_train_0, byrow=TRUE) == matrix(pred_by_xgboost_0, byrow=TRUE)))
expect_true(all(matrix(pred_by_train_1, byrow=TRUE) == matrix(pred_by_xgboost_1, byrow=TRUE)))
expect_true(all(matrix(pred_by_train_2, byrow=TRUE) == matrix(pred_by_xgboost_2, byrow=TRUE)))
})
test_that("train and predict softprob", {
lb <- as.numeric(iris$Species) - 1
set.seed(11)
expect_output(
bst <- xgboost(data = as.matrix(iris[, -5]), label = lb,
max_depth = 3, eta = 0.5, nthread = 2, nrounds = 5,
objective = "multi:softprob", num_class=3)
, "train-merror")
expect_false(is.null(bst$evaluation_log))
expect_lt(bst$evaluation_log[, min(train_merror)], 0.025)
expect_equal(bst$niter * 3, xgb.ntree(bst))
pred <- predict(bst, as.matrix(iris[, -5]))
expect_length(pred, nrow(iris) * 3)
# row sums add up to total probability of 1:
expect_equal(rowSums(matrix(pred, ncol=3, byrow=TRUE)), rep(1, nrow(iris)), tolerance = 1e-7)
# manually calculate error at the last iteration:
mpred <- predict(bst, as.matrix(iris[, -5]), reshape = TRUE)
expect_equal(as.numeric(t(mpred)), pred)
pred_labels <- max.col(mpred) - 1
err <- sum(pred_labels != lb)/length(lb)
expect_equal(bst$evaluation_log[5, train_merror], err, tolerance = 5e-6)
# manually calculate error at the 1st iteration:
mpred <- predict(bst, as.matrix(iris[, -5]), reshape = TRUE, ntreelimit = 1)
pred_labels <- max.col(mpred) - 1
err <- sum(pred_labels != lb)/length(lb)
expect_equal(bst$evaluation_log[1, train_merror], err, tolerance = 5e-6)
})
test_that("train and predict softmax", {
lb <- as.numeric(iris$Species) - 1
set.seed(11)
expect_output(
bst <- xgboost(data = as.matrix(iris[, -5]), label = lb,
max_depth = 3, eta = 0.5, nthread = 2, nrounds = 5,
objective = "multi:softmax", num_class=3)
, "train-merror")
expect_false(is.null(bst$evaluation_log))
expect_lt(bst$evaluation_log[, min(train_merror)], 0.025)
expect_equal(bst$niter * 3, xgb.ntree(bst))
pred <- predict(bst, as.matrix(iris[, -5]))
expect_length(pred, nrow(iris))
err <- sum(pred != lb)/length(lb)
expect_equal(bst$evaluation_log[5, train_merror], err, tolerance = 5e-6)
})
test_that("train and predict RF", {
set.seed(11)
lb <- train$label
# single iteration
bst <- xgboost(data = train$data, label = lb, max_depth = 5,
nthread = 2, nrounds = 1, objective = "binary:logistic",
num_parallel_tree = 20, subsample = 0.6, colsample_bytree = 0.1)
expect_equal(bst$niter, 1)
expect_equal(xgb.ntree(bst), 20)
pred <- predict(bst, train$data)
pred_err <- sum((pred > 0.5) != lb)/length(lb)
expect_lt(abs(bst$evaluation_log[1, train_error] - pred_err), 10e-6)
#expect_lt(pred_err, 0.03)
pred <- predict(bst, train$data, ntreelimit = 20)
pred_err_20 <- sum((pred > 0.5) != lb)/length(lb)
expect_equal(pred_err_20, pred_err)
#pred <- predict(bst, train$data, ntreelimit = 1)
#pred_err_1 <- sum((pred > 0.5) != lb)/length(lb)
#expect_lt(pred_err, pred_err_1)
#expect_lt(pred_err, 0.08)
})
test_that("train and predict RF with softprob", {
lb <- as.numeric(iris$Species) - 1
nrounds <- 15
set.seed(11)
bst <- xgboost(data = as.matrix(iris[, -5]), label = lb,
max_depth = 3, eta = 0.9, nthread = 2, nrounds = nrounds,
objective = "multi:softprob", num_class=3, verbose = 0,
num_parallel_tree = 4, subsample = 0.5, colsample_bytree = 0.5)
expect_equal(bst$niter, 15)
expect_equal(xgb.ntree(bst), 15*3*4)
# predict for all iterations:
pred <- predict(bst, as.matrix(iris[, -5]), reshape=TRUE)
expect_equal(dim(pred), c(nrow(iris), 3))
pred_labels <- max.col(pred) - 1
err <- sum(pred_labels != lb)/length(lb)
expect_equal(bst$evaluation_log[nrounds, train_merror], err, tolerance = 5e-6)
# predict for 7 iterations and adjust for 4 parallel trees per iteration
pred <- predict(bst, as.matrix(iris[, -5]), reshape=TRUE, ntreelimit = 7 * 4)
err <- sum((max.col(pred) - 1) != lb)/length(lb)
expect_equal(bst$evaluation_log[7, train_merror], err, tolerance = 5e-6)
})
test_that("use of multiple eval metrics works", {
expect_output(
bst <- xgboost(data = train$data, label = train$label, max_depth = 2,
eta = 1, nthread = 2, nrounds = 2, objective = "binary:logistic",
eval_metric = 'error', eval_metric = 'auc', eval_metric = "logloss")
, "train-error.*train-auc.*train-logloss")
expect_false(is.null(bst$evaluation_log))
expect_equal(dim(bst$evaluation_log), c(2, 4))
expect_equal(colnames(bst$evaluation_log), c("iter", "train_error", "train_auc", "train_logloss"))
})
test_that("training continuation works", {
dtrain <- xgb.DMatrix(train$data, label = train$label)
watchlist = list(train=dtrain)
param <- list(objective = "binary:logistic", max_depth = 2, eta = 1, nthread = 2)
# for the reference, use 4 iterations at once:
set.seed(11)
bst <- xgb.train(param, dtrain, nrounds = 4, watchlist, verbose = 0)
# first two iterations:
set.seed(11)
bst1 <- xgb.train(param, dtrain, nrounds = 2, watchlist, verbose = 0)
# continue for two more:
bst2 <- xgb.train(param, dtrain, nrounds = 2, watchlist, verbose = 0, xgb_model = bst1)
if (!windows_flag && !solaris_flag)
expect_equal(bst$raw, bst2$raw)
expect_false(is.null(bst2$evaluation_log))
expect_equal(dim(bst2$evaluation_log), c(4, 2))
expect_equal(bst2$evaluation_log, bst$evaluation_log)
# test continuing from raw model data
bst2 <- xgb.train(param, dtrain, nrounds = 2, watchlist, verbose = 0, xgb_model = bst1$raw)
if (!windows_flag && !solaris_flag)
expect_equal(bst$raw, bst2$raw)
expect_equal(dim(bst2$evaluation_log), c(2, 2))
# test continuing from a model in file
xgb.save(bst1, "xgboost.model")
bst2 <- xgb.train(param, dtrain, nrounds = 2, watchlist, verbose = 0, xgb_model = "xgboost.model")
if (!windows_flag && !solaris_flag)
expect_equal(bst$raw, bst2$raw)
expect_equal(dim(bst2$evaluation_log), c(2, 2))
})
test_that("xgb.cv works", {
set.seed(11)
expect_output(
cv <- xgb.cv(data = train$data, label = train$label, max_depth = 2, nfold = 5,
eta = 1., nthread = 2, nrounds = 2, objective = "binary:logistic",
verbose=TRUE)
, "train-error:")
expect_is(cv, 'xgb.cv.synchronous')
expect_false(is.null(cv$evaluation_log))
expect_lt(cv$evaluation_log[, min(test_error_mean)], 0.03)
expect_lt(cv$evaluation_log[, min(test_error_std)], 0.008)
expect_equal(cv$niter, 2)
expect_false(is.null(cv$folds) && is.list(cv$folds))
expect_length(cv$folds, 5)
expect_false(is.null(cv$params) && is.list(cv$params))
expect_false(is.null(cv$callbacks))
expect_false(is.null(cv$call))
})
test_that("xgb.cv works with stratified folds", {
dtrain <- xgb.DMatrix(train$data, label = train$label)
set.seed(314159)
cv <- xgb.cv(data = dtrain, max_depth = 2, nfold = 5,
eta = 1., nthread = 2, nrounds = 2, objective = "binary:logistic",
verbose=TRUE, stratified = FALSE)
set.seed(314159)
cv2 <- xgb.cv(data = dtrain, max_depth = 2, nfold = 5,
eta = 1., nthread = 2, nrounds = 2, objective = "binary:logistic",
verbose=TRUE, stratified = TRUE)
# Stratified folds should result in a different evaluation logs
expect_true(all(cv$evaluation_log[, test_error_mean] != cv2$evaluation_log[, test_error_mean]))
})
test_that("train and predict with non-strict classes", {
# standard dense matrix input
train_dense <- as.matrix(train$data)
bst <- xgboost(data = train_dense, label = train$label, max_depth = 2,
eta = 1, nthread = 2, nrounds = 2, objective = "binary:logistic", verbose = 0)
pr0 <- predict(bst, train_dense)
# dense matrix-like input of non-matrix class
class(train_dense) <- 'shmatrix'
expect_true(is.matrix(train_dense))
expect_error(
bst <- xgboost(data = train_dense, label = train$label, max_depth = 2,
eta = 1, nthread = 2, nrounds = 2, objective = "binary:logistic", verbose = 0)
, regexp = NA)
expect_error(pr <- predict(bst, train_dense), regexp = NA)
expect_equal(pr0, pr)
# dense matrix-like input of non-matrix class with some inheritance
class(train_dense) <- c('pphmatrix','shmatrix')
expect_true(is.matrix(train_dense))
expect_error(
bst <- xgboost(data = train_dense, label = train$label, max_depth = 2,
eta = 1, nthread = 2, nrounds = 2, objective = "binary:logistic", verbose = 0)
, regexp = NA)
expect_error(pr <- predict(bst, train_dense), regexp = NA)
expect_equal(pr0, pr)
# when someone inhertis from xgb.Booster, it should still be possible to use it as xgb.Booster
class(bst) <- c('super.Booster', 'xgb.Booster')
expect_error(pr <- predict(bst, train_dense), regexp = NA)
expect_equal(pr0, pr)
})
test_that("max_delta_step works", {
dtrain <- xgb.DMatrix(agaricus.train$data, label = agaricus.train$label)
watchlist <- list(train = dtrain)
param <- list(objective = "binary:logistic", eval_metric="logloss", max_depth = 2, nthread = 2, eta = 0.5)
nrounds = 5
# model with no restriction on max_delta_step
bst1 <- xgb.train(param, dtrain, nrounds, watchlist, verbose = 1)
# model with restricted max_delta_step
bst2 <- xgb.train(param, dtrain, nrounds, watchlist, verbose = 1, max_delta_step = 1)
# the no-restriction model is expected to have consistently lower loss during the initial interations
expect_true(all(bst1$evaluation_log$train_logloss < bst2$evaluation_log$train_logloss))
expect_lt(mean(bst1$evaluation_log$train_logloss)/mean(bst2$evaluation_log$train_logloss), 0.8)
})
test_that("colsample_bytree works", {
# Randomly generate data matrix by sampling from uniform distribution [-1, 1]
set.seed(1)
train_x <- matrix(runif(1000, min = -1, max = 1), ncol = 100)
train_y <- as.numeric(rowSums(train_x) > 0)
test_x <- matrix(runif(1000, min = -1, max = 1), ncol = 100)
test_y <- as.numeric(rowSums(test_x) > 0)
colnames(train_x) <- paste0("Feature_", sprintf("%03d", 1:100))
colnames(test_x) <- paste0("Feature_", sprintf("%03d", 1:100))
dtrain <- xgb.DMatrix(train_x, label = train_y)
dtest <- xgb.DMatrix(test_x, label = test_y)
watchlist <- list(train = dtrain, eval = dtest)
# Use colsample_bytree = 0.01, so that roughly one out of 100 features is
# chosen for each tree
param <- list(max_depth = 2, eta = 0, verbosity = 0, nthread = 2,
colsample_bytree = 0.01, objective = "binary:logistic",
eval_metric = "auc")
set.seed(2)
bst <- xgb.train(param, dtrain, nrounds = 100, watchlist, verbose = 0)
xgb.importance(model = bst)
# If colsample_bytree works properly, a variety of features should be used
# in the 100 trees
expect_gte(nrow(xgb.importance(model = bst)), 30)
})
test_that("Configuration works", {
bst <- xgboost(data = train$data, label = train$label, max_depth = 2,
eta = 1, nthread = 2, nrounds = 2, objective = "binary:logistic",
eval_metric = 'error', eval_metric = 'auc', eval_metric = "logloss")
config <- xgb.config(bst)
xgb.config(bst) <- config
reloaded_config <- xgb.config(bst)
expect_equal(config, reloaded_config);
})