R 预测模型决策树
我想在R中使用决策树分类构建预测模型。我使用以下代码:R 预测模型决策树,r,r-caret,R,R Caret,我想在R中使用决策树分类构建预测模型。我使用以下代码: library(rpart) library(caret) DataYesNo <- read.csv('DataYesNo.csv', header=T) summary(DataYesNo) worktrain <- sample(1:50, 40) worktest <- setdiff(1:50, worktrain) DataYesNo[worktrain,] DataYesNo[worktest,] M
library(rpart)
library(caret)
DataYesNo <- read.csv('DataYesNo.csv', header=T)
summary(DataYesNo)
worktrain <- sample(1:50, 40)
worktest <- setdiff(1:50, worktrain)
DataYesNo[worktrain,]
DataYesNo[worktest,]
M <- ncol(DataYesNo)
input <- names(DataYesNo)[1:(M-1)]
target <- “YesNo”
tree <- rpart(YesNo~Var1+Var2+Var3+Var4+Var5,
data=DataYesNo[worktrain, c(input,target)],
method="class",
parms=list(split="information"),
control=rpart.control(usesurrogate=0, maxsurrogate=0))
summary(tree)
plot(tree)
text(tree)
我只有一个根变量3和两个叶是的,不是。我不确定这个结果。如何获得混淆矩阵、准确性、敏感性和特异性?
我可以用插入符号包获取它们吗?如果您使用模型对测试集进行预测,则可以使用confusionMatrix获取您要寻找的度量值 像这样的
predictions <- predict(tree, worktest)
cmatrix <- confusionMatrix(predictions, worktest$YesNo)
print(cmatrix)
一旦你创建了一个混乱矩阵,其他的度量也可以得到——我现在不记得了 根据您的示例,混淆矩阵可如下所示
fitted <- predict(tree, DataYesNo[worktest, c(input,target)])
actual <- DataYesNo[worktest, c(target)]
confusion <- table(data.frame(fitted = fitted, actual = actual))