介绍了一些简单的绘图函数，需要更难的操作还需要去查文档

> data(cars) #load data
> head(cars)
  speed dist
1     4    2
2     4   10
3     7    4
4     7   22
5     8   16
6     9   10
> plot(x = cars$speed, y = cars$dist, ylab = "Stopping Distance", xlab = "Speed", main = "My Plot", sub = "My Plot Subtitle", , col = 2) # 图1
> plot(cars, xlim = c(10, 15),  pch = 2) # 图2

> data(mtcars)
> boxplot(formula = mpg ~ cyl, data = mtcars) # 图3
> hist(mtcars$mpg) # 图4