Error in terms.formula(formula, data = data) : invalid model formula in ExtractVars

Error in terms.formula(formula, data = data) :invalid model formula in ExtractVars

目录

Error in terms.formula(formula, data = data) :invalid model formula in ExtractVars

问题：

解决：

完整问题：

---

问题：

公式中的预测变量不需要加引号；

#create data frame
df <- data.frame(rating=c(88, 94, 99, 90, 76, 78, 81, 88),
                 points=c(14, 17, 22, 24, 25, 22, 29, 31),
                 assists=c(7, 7, 6, 12, 10, 11, 17, 2),
                 rebounds=c(7, 8, 8, 12, 9, 5, 11, 15))

#view data frame
df

library(rpart)

#attempt to fit decision tree model to data
model <- rpart(rating ~ "points" + "assists" + "rebounds", data = df)

解决：

公式中的预测变量不需要加引号；

library(rpart)

#fit decision tree model
model <- rpart(rating ~ points + assists + rebounds, data = df)

#view summary of model
summary(model)

完整问题：

> library(rpart)
> 
> #attempt to fit decision tree model to data
> model <- rpart(rating ~ "points" + "assists" + "rebounds", data = df)
Error in terms.formula(formula, data = data) : 
  ExtractVars里的模型公式不对
>