R in action -- 2.2 数据结构

R in action -- 2.1 数据结构

1、因子及因子的使用

2、列表是若干对象的有序集合

> g <- "My First List"
> h <- c(25,26,18,39)
> j <- matrix(1:10, nrow = 5)
> k <- c("one","two","threee")
> mylist <- list(title=g,ages=h,j,k)
> mylist
$title
[1] "My First List"

$ages
[1] 25 26 18 39

[[3]]
     [,1] [,2]
[1,]    1    6
[2,]    2    7
[3,]    3    8
[4,]    4    9
[5,]    5   10

[[4]]
[1] "one"    "two"    "threee"

> mylist[2]
$ages
[1] 25 26 18 39

> mylist[["ages"]]
[1] 25 26 18 39
> mylist[[2]]
[1] 25 26 18 39
> mylist["ages"]
$ages
[1] 25 26 18 39