我试图在目标是多类分类的数据集上在 R 中训练 ML 算法(rf、adaboost、xgboost)。对于超参数调整,我使用 MLR 包。
下面代码的目标是调整参数 mtry 和 nodesize,但将 ntrees 保持在 128(使用 mlrMBO)。但是,我收到以下错误消息。如何以正确的方式定义它?
rdesc <- makeResampleDesc("CV",stratify = T,iters=10L)
traintask <- makeClassifTask(data = df_train,
target = "more_than_X_perc_damage")
testtask <- makeClassifTask(data = df_test,
target = "more_than_X_perc_damage")
lrn <- makeLearner("classif.randomForest",
predict.type = "prob")
# parameter space
params_to_tune <- makeParamSet(makeIntegerParam("ntree", lower = 128, upper = 128),
makeNumericParam("mtry", lower = 0, upper = 1, trafo = function(x) ceiling(x*ncol(train_x))),
makeNumericParam("nodesize",lower = 0,upper = 1, trafo = function(x) ceiling(nrow(train_x)^x)))
ctrl = makeTuneControlMBO(mbo.control=mlrMBO::makeMBOControl())
tuned_params <- tuneParams(learner = lrn,
task = traintask,
control = ctrl,
par.set = params_to_tune,
resampling = rdesc,
measure=acc)
rf_tuned_learner <- setHyperPars(learner = lrn,
par.vals = tuned_params$x)
rf_tuned_model <- mlr::train(rf_tuned_learner, traintask)
# prediction performance
pred <- predict(rf_tuned_model, testtask)
performance(pred)
calculateConfusionMatrix(pred)
stats <- confusionMatrix(pred$data$response,pred$data$truth)
acc_rf_tune <- stats$overall[1] # accuracy
print(acc_rf_tune)
(function (fn, nvars, max = FALSE, pop.size = 1000, max.generations = 100, : Domains[,1] 必须小于或等于 Domains[,2]
提前致谢!