This document provides information about R programming language. It discusses that R was created by Ross Ihaka and Robert Gentleman in 1993 and is currently developed by R Core Team. It is the most widely used statistical programming language. The document then provides information about downloading and installing R and R Studio. It also gives examples of basic R functions and concepts like data types, vectors, conditional statements, and loops.

1. GOSSEM
https://cafe.naver.com/gossemaction

2. • R
• R 환경
• R Studio
• R 기초
• R 기초 함수
• Types - 데이터타입
• Vector
• 조건문
• 반복문

3.  R was created by Ross Ihaka and Robert Gentleman at the University
of Auckland, New Zealand
 currently developed by the R Development Core Team.
 This programming language was named R, based on the first letter
of first name of the two R authors (Robert Gentleman and Ross Ihaka)
 R made its first appearance in 1993.
 Since mid-1997 there has been a core group (the "R Core Team")
who can modify the R source code archive.
 world’s most widely used statistics programming language

4. software environment for statistical analysis, graphics
representation and reporting.
 if your windows is 64-bit, then it installs both the 32-bit and 64-
bit versions.
 Download
 https://cloud.r-project.org/

5. programming language for statistical analysis, graphics
representation and reporting.
 Download R Studio
 https://www.rstudio.com/products/rstudio/download/#downlo
ad

6.  화면지우기
 Ctrl + L
 도움말보기
 ?명령어
 ?print

7.  R Studio
 주석
 한줄 주석
 #

8. - concat
- 값을 연결해서 출력
> num.1 = c(1,2,3)
> num.2 = c(4,5,6)
> print(class(num.1))
[1] "numeric"
> cat(num.1, num.2)
1 2 3 4 5 6

9. - 현재 워크스페이스의 변수목록을 리턴
> ls()
[1] "apple_colors" "BMI" "factor_apple"
[4] "num.1" "num.2" "sum.0"
> print(class(ls()))
[1] "character"

10. - 변수를 삭제함
> ls()
[1] "apple_colors" "BMI" "factor_apple"
[4] "num.1" "num.2" "sum.0"
> print(class(ls()))
[1] "character"
> rm(BMI)
> ls()
[1] "apple_colors" "factor_apple" "num.1"
[4] "num.2" "sum.0"
> rm(sum.0)
> ls()
[1] "apple_colors" "factor_apple" "num.1"
[4] "num.2"

11. > print(class(TRUE))
[1] "logical"
> print(class(FALSE))
[1] "logical"

12. • numeric
• 표기
• 수만입력
• 표현범위
• 제한 없음
> print(class(7))
[1] "numeric"
> print(class(7.7))
[1] "numeric"
> print(class(7777777777777777777777777777777))
[1] "numeric"
>
print(class(7777777777777777777777777777777777777777777777777777777
7777777777777777777777777777777777777777777777777777777777777777
77777777777777777777777777777777777777777777777))
[1] "numeric"

13. • Integer
• 표기
• 수L
• 정수 9자리까지만 표현 가능
> print(class(7L))
[1] "integer"
> print(class(77L))
[1] "integer"
> print(class(777L))
[1] "integer"
> print(class(7777L))
[1] "integer"
> print(class(77777L))
[1] "integer"
> print(class(777777L))
[1] "integer"
> print(class(7777777L))
[1] "integer"
> print(class(77777777L))
[1] "integer"
> print(class(777777777L))
[1] "integer"
> print(class(7777777777L))
[1] "numeric"
Warning message:
non-integer value 7777777777L qualified with L; using numeric value

14. > print(class('7'))
[1] "character"
> print(class("7"))
[1] "character"
> print(class("7.7"))
[1] "character"
> print(class("hong"))
[1] "character"

15. A vector is a sequence of data elements of the same basic type
1차원 배열

16. > print(c(1:7))
[1] 1 2 3 4 5 6 7
> print(c(3:-3))
[1] 3 2 1 0 -1 -2 -3

17. > seq(from=1, to=10, by=2)
[1] 1 3 5 7 9
> seq(1,10,2)
[1] 1 3 5 7 9
> seq(1, 3, by=0.3)
[1] 1.0 1.3 1.6 1.9 2.2 2.5 2.8
> is.vector(seq(1, 3, by=0.3))
[1] TRUE
> seq(1, 5, length=3)
[1] 1 3 5
> seq(1, 5, length=4)
[1] 1.000000 2.333333 3.666667 5.000000
> seq(1, 5, length=10)
[1] 1.000000 1.444444 1.888889 2.333333 2.777778
[6] 3.222222 3.666667 4.111111 4.555556 5.000000

18. > x <- 1:4
> print(x)
[1] 1 2 3 4
> #start
> c(1,3:5)
[1] 1 3 4 5
> c(1:10,20.5, "start")
[1] "1" "2" "3" "4" "5" "6" "7" "8" "9"
"10" "20.5" "start“
> x = c(1,2,3)
> x+1
[1] 2 3 4

19. charactor vector를 키로 사용가능
> x <- c('tom'='tom is a good boy', 'john'='john is a kind bo
dy')
> x['tom']
tom
"tom is a good boy"
> x['john']
john
"john is a kind body"

20. > rep(c(1,2,3), each=2, times=3)
[1] 1 1 2 2 3 3 1 1 2 2 3 3 1 1 2 2
[17] 3 3

21. > g <- seq(0, 10, 2)
> g
[1] 0 2 4 6 8 10
> g[1]
[1] 0
> g[c(2,4)]
[1] 2 6
> g[-1]
[1] 2 4 6 8 10
> g[1.1]
[1] 0
> g[2.9]
[1] 2

22. > g <- seq(0, 10, 2)
> g[c(TRUE, FALSE, TRUE, FALSE, TRUE, FALSE)]
[1] 0 4 8
> g[ g > 4]
[1] 6 8 10

23.  벡터를 팩터화
◦ 벡터에 levels 라는 키가 추가되어 팩터가 됨.
> # Apply the factor function.
> factor_data <- factor(data)
>
> print(factor_data)
[1] East West East North North East West West We
st
[10] East North
Levels: East North West

24.  팩터인지 아닌지 확인
> # Create a vector as input.
> data <- c("East","West","East","North","North","East","We
st","West","West","East","North")
>
> print(data)
[1] "East" "West" "East" "North" "North" "East" "West"
[8] "West" "West" "East" "North"
> print(is.factor(data))
[1] FALSE

25. 펙터에서 LEVEL만 추출해서 벡터로 리턴
> data <- c("East","West","East","North","North","East",
"West","West","West","East","North")
> factor_data <- factor(data)
> levels(factor_data)
[1] "East" "North" "West"

26.  레벨값을 복사해서 벡터 생성
> v <- gl(3, 4, labels = c("Tampa", "Seattle","Boston"))
> print(v)
[1] Tampa Tampa Tampa Tampa Seattle Seattle
Seattle
[8] Seattle Boston Boston Boston Boston
Levels: Tampa Seattle Boston

27. x <- 5
if(x > 0){
print("Positive number")
}

28. > x <- -5
> y <- if(x > 0) 5 else 6
> y
[1] 6

29. x <- c(2,5,3,9,8,11,6)
count <- 0
for (val in x) {
if(val %% 2 == 0) count = count+1
}
print(count)

30. i <- 1
while (i < 6) {
print(i)
i = i+1
}

31. x <- 1:5
for (val in x) {
if (val == 3){
break
}
print(val)
}
[1] 1
[1] 2

32. x <- 1:5
for (val in x) {
if (val == 3){
next
}
print(val)
}
[1] 1
[1] 2
[1] 4
[1] 5