R将几个虚拟变量列合并为1

Question

我正在尝试合并汽车数据框(插入符号包)中的几个列.列"敞篷车,轿跑车,掀背车,轿车,旅行车"都有虚拟变量,我想创建一个名为type的列,其列名取决于车辆的类型.

library(caret)
data(cars)
head(cars)
colnames(cars)

以下是汽车数据框的列名:

 [1] "Price"       "Mileage"     "Cylinder"    "Doors"       "Cruise"        
 [6] "Sound"       "Leather"     "Buick"       "Cadillac"    "Chevy"     
[11] "Pontiac"     "Saab"        "Saturn"      "convertible" "coupe"   
[16] "hatchback"   "sedan"       "wagon" 

如何将最后5个虚拟变量列合并/合并为1与相应的车辆类型？

任何见解或帮助将不胜感激!

Answer 1

矢量化解决方案max.col:

cars$type <- names(cars[14:18])[max.col(cars[14:18])]

作为替代解决方案,您可以使用match:

cars$type <- names(cars[14:18])[apply(cars[14:18], 1, match, x = 1)] 

Answer 2

ind <- apply(cars[,14:18],1,function(x) which(as.logical(x)))
cars$type <- colnames(cars[,14:18])[ind]
head(cars)