r - -train 中的错误：一元运算符的参数无效

Question

我正在使用 R Studio 并试图编织一个文件。下面的代码块将作为块运行，但当我尝试编织文件时会引发错误。

tree.corolla <- rpart(Price ~ ., data = toyota.corolla.df, control = rpart.control(maxdepth = 5), method = "anova") 

我得到的错误是：

-train 中的错误：一元运算符调用的参数无效：... eval -> predict -> predict.rpart -> [ -> [.data.frame

我正在使用 ToyotaCorolla.csv 数据集，可在此处获得：

https://pitt.box.com/s/e0rhjtba8az85epqus9xu85e4q6zxuts

整个代码块如下：

#install.packages("rpart")
#install.packages("rpart.plot")
#install.packages("gbm")
#install.packages("randomForest")
#install.packages("dummies")
library(randomForest)
library(gbm)
library(rpart)
library(rpart.plot)
library(tree)
library(ISLR)
library(dummies)
library(adabag)
library(rpart) 
library(caret)
toyota.corolla.df <- read.csv("ToyotaCorolla.csv")
#View(toyota.corolla.df)
# randomly generate training and validation sets
toyota.corolla.df <- toyota.corolla.df[ , -c(1, 2, 5, 6)]

toyota.corolla.df <- cbind(toyota.corolla.df, dummy(toyota.corolla.df$Fuel_Type, sep = "_"))
toyota.corolla.df <- cbind(toyota.corolla.df, dummy(toyota.corolla.df$Color, sep = "_"))
toyota.corolla.df <- toyota.corolla.df[ , -c(4, 7)]
set.seed(123)
inTraining <- createDataPartition(toyota.corolla.df$Price, p = .60, list = FALSE)
training <- toyota.corolla.df[ inTraining,]
testing  <- toyota.corolla.df[-inTraining,]
tree.corolla <- rpart(Price ~ ., data = toyota.corolla.df, control = rpart.control(maxdepth = 5), method = "anova") 

summary(tree.corolla)
plot(tree.corolla)
text(tree.corolla,pretty=0)
cv.corolla=trainControl(method = "repeatedcv", number = 10, repeats = 10)
prp(tree.corolla, type = 1, extra = 1, split.font = 1, varlen = -10)
yhat=predict(tree.corolla,newdata=toyota.corolla.df[-train,])
corolla.test=toyota.corolla.df[-train,"Price"]
plot(yhat,corolla.test)
abline(0,1)

标签： rrpart