R语言实战 - 基本统计分析（1）- 描述性统计分析

> vars <- c("mpg", "hp", "wt")
> head(mtcars[vars])
                   mpg  hp    wt
Mazda RX4         21.0 110 2.620
Mazda RX4 Wag     21.0 110 2.875
Datsun 710        22.8  93 2.320
Hornet 4 Drive    21.4 110 3.215
Hornet Sportabout 18.7 175 3.440
Valiant           18.1 105 3.460
> 
> vars <- c("mpg", "hp", "wt")
> head(mtcar