显示标签而不是rpart.plot中的变量名？

Question

我已绘制了一棵树，理想情况下，我希望该树显示变量的所有标签。例如，显示“花费的时间”（我对变量的标签）而不是“ time_reading”（变量）。特别是到目前为止，我使用的是rpart.plot包：

tree1 <- ...
rpart.plot(tree1)

并且所有节点都显示变量名称，而不是标签。如何添加标签命令以用标签替换变量名？预先感谢您的帮助！

Answer 1

在绘图树中获取所需变量名称的一种方法是更改​​变量树中的变量名称。原始数据。例如：

data(ptitanic)
mytitanic <- ptitanic
colnames(mytitanic) <- c("passenger class", "survived", "sex",
  "age in years", "number siblings or spouses",
  "number parents or children")
tree1 <- rpart(survived~., data=mytitanic)
rpart.plot(tree1)

另一种方法是使用split.fun参数。有关详细信息，请参见vignette for the rpart.plot package第6.1节。例如：

data(ptitanic)
tree2 <- rpart(survived~., data=ptitanic)
split.fun <- function(x, labs, digits, varlen, faclen)
{
    # replace variable names in the labels
    labs   <- sub("pclass",   "passenger class", labs)
    # labs <- sub("survived", "survived", labs)
    # labs <- sub("sex",      "sex", labs)
    labs   <- sub("age",      "age in years", labs)
    labs   <- sub("sibsp",    "number siblings or spouses", labs)
    labs   <- sub("parch",    "number parents or children", labs)

    labs # return the modified labels
}
rpart.plot(tree2, split.fun=split.fun)