(macOS)[R] data structure : vector, matrix, dataframe

INTRO

1. 백터 : vector

2. 행렬 : matrix

3. 데이터 프레임 : dataframe

 

1. Vector

- 하나 이상의 스칼라 원소들을 갖는 집합

- 숫자, 문자, 논리 연산자 등

- 'c'(concentration, 연결)를 통해 선언

 

2. Matrix

- m(행,row) x n(열,col) 형태 데이터 구조

 

3. DataFrame

- R에서 가장 널리 사용

- 2차원 목록 데이터 구조

 

test_data.R

## vector by c
x1 = c(1,10,24,40)
y1 = c("사과", "바나나", "오렌지")
z1 = c(TRUE, FALSE, TRUE)

x2 <- c(1,10,24,40)
y2 <- c("사과", "바나나", "오렌지")
z2 <- c(TRUE, FALSE, TRUE)

## vector combine
xy1 <- c(x2, y2)


## matrix
mx1 = matrix(c(1,2,3,4,5,6), ncol=2)
mx2 = matrix(c(1,2,3,4,5,6), ncol=2, byrow=T) #ncol but row first
mx3 = matrix(c(1,2,3,4,5,6), nrow=2)

## matrix ncol, nrow print
print(mx1)
print(mx2)
print(mx3)

## matrix combine rbind, cbind
r1 = c(10,20)
c1 = c(10,20,30)

print(rbind(mx1,r1))
print(cbind(mx1,c1))


## dataframe 2-dimesion data
income = c(100,200,150,300,900)
car = c("kia","hyundai","kia","toyota","lexus")
marriage = c(FALSE,FALSE,FALSE,TRUE,TRUE)
mydat = data.frame(income,car,marriage)
print(mydat)

 

 

출력결과 : command+shift+Enter

> ## vector by c
> x1 = c(1,10,24,40)

> y1 = c("사과", "바나나", "오렌지")

> z1 = c(TRUE, FALSE, TRUE)

> x2 <- c(1,10,24,40)

> y2 <- c("사과", "바나나", "오렌지")

> z2 <- c(TRUE, FALSE, TRUE)

> ## vector combine
> xy1 <- c(x2, y2)

> ## matrix
> mx1 = matrix(c(1,2,3,4,5,6), ncol=2)

> mx2 = matrix(c(1,2,3,4,5,6), ncol=2, byrow=T) #ncol but row first

> mx3 = matrix(c(1,2,3,4,5,6), nrow=2)

> ## matrix ncol, nrow print
> print(mx1)
     [,1] [,2]
[1,]    1    4
[2,]    2    5
[3,]    3    6

> print(mx2)
     [,1] [,2]
[1,]    1    2
[2,]    3    4
[3,]    5    6

> print(mx3)
     [,1] [,2] [,3]
[1,]    1    3    5
[2,]    2    4    6

> ## matrix combine rbind, cbind
> r1 = c(10,20)

> c1 = c(10,20,30)

> print(rbind(mx1,r1))
   [,1] [,2]
      1    4
      2    5
      3    6
r1   10   20

> print(cbind(mx1,c1))
         c1
[1,] 1 4 10
[2,] 2 5 20
[3,] 3 6 30

> ## dataframe 2-dimesion data
> income = c(100,200,150,300,900)

> car = c("kia","hyundai","kia","toyota","lexus")

> marriage = c(FALSE,FALSE,FALSE,TRUE,TRUE)

> mydat = data.frame(income,car,marriage)

> print(mydat)
  income     car marriage
1    100     kia    FALSE
2    200 hyundai    FALSE
3    150     kia    FALSE
4    300  toyota     TRUE
5    900   lexus     TRUE