| 函数名 | 功能 | 例子 | 例子效果 |
| print() | 打印 | print ( "hello world") | "hello world" |
| c() | 把多个向量拼成数组 | apple<-c("red","green"); print(apple); print(class(apple)) | [1] "red" "green" [1] "character" |
| list() | 组合出列表变量 | list1<-list(c(2,5,3),21.3,sin); print(list1) | [[1]] [1] 2 5 3[[2]] [1] 21.3[[3]] function (x) .Primitive("sin") |
| matrix() | 生成 矩阵型 变量 | M=matrix(c('a','a','b'),nrow=2,ncol=3,byrow=TRUE); print(M) | [,1] [,2] [,3][1,] "a" "a" "b" [2,] "a" "a" "b" |
| if() {} | 决策 | x<-30L; if(is.integer(x)) {print("X is an Integer") } | "X is an Integer" |
| if() {} else {} | 决策 | ||
| if ... else if ... else | 决策 | ||
| switch(exp , case1, case2, case3...) | 决策 | x<-switch(3,"one","two","three"); print(x) | "three" |
| repeat { commands if(condition) { break } } | 循环 | v <- c("Hello","loop") cnt <- 2 repeat { print(v) cnt <- cnt+1 if(cnt > 5) { break } } | [1] "Hello" "loop" [1] "Hello" "loop" [1] "Hello" "loop" [1] "Hello" "loop" |
| while | 一次又一次地执行相同的代码，直到满足停止条件 while (exp) { statement } | v <- c("Hello","while loop") cnt <- 2 while (cnt < 7) { print(v) cnt = cnt + 1 } | [1] "Hello" "while loop" [1] "Hello" "while loop"[1] "Hello" "while loop"[1] "Hello" "while loop"[1] "Hello" "while loop" |
| for | for (exp) { statement } | v <- LETTERS[1:4]; for ( i in v) { print(i) } | [1] "A" [1] "B"[1] "C"[1] "D" |
| cbind() | 连接多个向量，每个向量为一列 | city <- c("Tampa","Seattle","Hartford","Denver") state <- c("FL","WA","CT","CO")zipcode <- c(33602,98104,06161,80294) addresses <- cbind(city,state,zipcode); print(address) | city state zipcode [1,] "Tampa" "FL" "33602"[2,] "Seattle" "WA" "98104"[3,] "Hartford" "CT" "6161" [4,] "Denver" "CO" "80294" |
| rbind() | 上下合并两个数据帧 (类似 sql 的union all) | city <- c("Tampa","Seattle","Hartford","Denver") state <- c("FL","WA","CT","CO")zipcode <- c(33602,98104,06161,80294) all.addresses <- rbind(addresses,addresses); print(all.addresses) | city state zipcode [1,] "Tampa" "FL" "33602"[2,] "Seattle" "WA" "98104"[3,] "Hartford" "CT" "6161" [4,] "Denver" "CO" "80294"[5,] "Tampa" "FL" "33602"[6,] "Seattle" "WA" "98104"[7,] "Hartford" "CT" "6161" [8,] "Denver" "CO" "80294" |
| merge() | 合并两个数据帧，数据帧必须具有相同的列名，在其上进行合并 | ||