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似乎有是被调整模型时所产生的ROC /桑斯/规格之间的差异,通过对相同的数据集的模型进行的实际预测。我正在使用使用kernlab的ksvm的脱字符号。我没有遇到glm的这个问题。交叉验证的预测为插入符和SVM
data(iris)
library(caret)
iris <- subset(iris,Species == "versicolor" | Species == "setosa") # we need only two output classess
iris$noise <- runif(nrow(iris)) # add noise - otherwise the model is too "perfect"
iris$Species <- factor(iris$Species)
fitControl <- trainControl(method = "repeatedcv",number = 10, repeats = 5, savePredictions = TRUE, classProbs = TRUE, summaryFunction = twoClassSummary)
ir <- train(Species ~ Sepal.Length + noise, data=iris,method = "svmRadial", preProc = c("center", "scale"), trControl=fitControl,metric="ROC")
confusionMatrix(predict(ir), iris$Species, positive = "setosa")
getTrainperf(ir) # same as in the model summary
什么是这种差异的根源?哪些是“真正的”,交叉验证后的预测?