install.packages(“ rafalib”)库(rafalib)install.packages(“ swirl”)库(swirl) ## ----------------------- x <-c(2.23,3.45,1.87,2.11,7.33,18.34,19.23)均值(x) sum <-0 for(i in 1:25){sum = sum + i ^ 2} sum 车类(汽车) 车头 名称(汽车)[2] 汽车[,2] 平均值(汽车[,2]) 其中(汽车[,2] == 85) x <-1:10 y <-rnorm(10)图(x,y)f