R 尝试构建树时给出：`[.default`（xj，i）中出现错误：下标类型无效'；列表'；

运行以下代码：

library(tree)
library(ISLR)
library(dplyr)

Carseats <- Carseats %>% mutate(High = factor(ifelse(Sales <= 8, "No", "Yes")))

set.seed(2)
train_sample <- sample(nrow(Carseats), 200)
carseats_train <- Carseats[train_sample,]
carseats_test <- Carseats[-train_sample,]

tree.carseats <- tree(High~ . -Sales, Carseats, subset = carseats_train)

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这是什么原因？我该如何处理它？

我发现了我的错误。我对树的输入不正确。即

子集

参数。这需要一个表达式来指定要使用的子集

可以使用

列车样本

作为输入来固定代码

library(tree)
library(ISLR)
library(dplyr)

Carseats <- Carseats %>% mutate(High = factor(ifelse(Sales <= 8, "No", "Yes")))

set.seed(2)
train_sample <- sample(nrow(Carseats), 200)
carseats_test <- Carseats[-train_sample,]

tree.carseats <- tree(High~ . -Sales, Carseats, subset = train_sample)

库（树）
图书馆（ISLR）
图书馆（dplyr）
车座百分比变化（高=系数（如果其他（销售
library(tree)
library(ISLR)
library(dplyr)

Carseats <- Carseats %>% mutate(High = factor(ifelse(Sales <= 8, "No", "Yes")))

set.seed(2)
train_sample <- sample(nrow(Carseats), 200)
carseats_test <- Carseats[-train_sample,]

tree.carseats <- tree(High~ . -Sales, Carseats, subset = train_sample)