R语言

安装包 7k个

command+return 来运行

?

??

?gmail 来了解

 

> library(devtools)
> library(devtools)
> a <- "abc"
> a
[1] "abc"
> class(a)
[1] "character"
> a <- 0
> class(a)
[1] "numeric"
> a <- as.character(a)
> class(a)
[1] "character"
>

改变类型

homoeneous 同质

vector 

metrix

heterogeneous 异质

list

Data frame

 1 > a <- numeric(10) 
 2 > a
 3  [1] 0 0 0 0 0 0 0 0 0 0
 4 > a[2] <- -1 
 5 > a
 6  [1]  0 -1  0  0  0  0  0  0  0  0
 7 > a <- c(1,2,3,5,6,7,8)
 8 > a
 9 [1] 1 2 3 5 6 7 8
10 >

 

posted @ 2017-04-15 23:49  gkgy  阅读(191)  评论(0)  编辑  收藏  举报