R 언어 기본 공부 1

v.1 <- c("PI", 3.14, TRUE)

v.1

'PI'
'3.14'
'TRUE'

d <- c(1,3,2,4,5)

d

    1 
    3 
    2 
    4
    5 

sort(d)

    1 
    2  
    3 
    4 
    5

sort(d, decreasing = T) #내림차순

    5 
    4 
    3 
    2
    1

V.1 <- c()

V.1

NULL

V.1[1] <- 10

V.1

10

V.1[5] <- 50

V.1

    10
    <NA> 
    <NA>  
    <NA>	
    50

V.2 <- c(v.1, seq(60,90,10))

V.2

    'PI'
    '3.14'
    'TRUE'
	'60'
    '70'
    '80'
    '90'

v.1 <- 1:9

v.1

    1 
    2 
    3 
    4 
    5 
    6 
    7
    8 
    9

v.2 <- v.1 >5

v.2

     FALSE 
     FALSE 
     FALSE 
     FALSE 
     FALSE 
     TRUE 
     TRUE 
     TRUE 
     TRUE 

v.3 <- (v.1 %% 2 == 0)

v.3

 FALSE  
 TRUE 
 FALSE 
 TRUE 
 FALSE 
 TRUE 
 FALSE 
 TRUE 
 FALSE

v.1[v.3]

    2 
    4
    6
    8

#요인객체 생성 
f <- factor(c("low","high"))
f

<ol class=list-inline> <li>low</li> <li>high</li> </ol>

<summary style=display:list-item;cursor:pointer> Levels: </summary> <ol class=list-inline>
  • 'high'
  • 'low'
    • </ol> 
    ## gl 함수 : 요인 수열의 생성
f.1 <- gl(2,6,labels=c("male","female"))
f.1

    <ol class=list-inline> <li>male</li> <li>male</li> <li>male</li> <li>male</li> <li>male</li> <li>male</li> <li>female</li> <li>female</li> <li>female</li> <li>female</li> <li>female</li> <li>female</li> </ol>

    <summary style=display:list-item;cursor:pointer> Levels: </summary> <ol class=list-inline>
  • 'male'
  • 'female'
    • </ol> 
    #### gl 함수 : 요인 수열의 생성
f.1 <- gl(1,6,labels=c("male","female"))
f.1

    <ol class=list-inline> <li>male</li> <li>male</li> <li>male</li> <li>male</li> <li>male</li> <li>male</li> </ol>

    <summary style=display:list-item;cursor:pointer> Levels: </summary> <ol class=list-inline>
  • 'male'
  • 'female'
    • </ol> 
    f.1 <- gl(0,7,labels=c("male","female"))
f.1
    <summary style=display:list-item;cursor:pointer> Levels: </summary> <ol class=list-inline>
  • 'male'
  • 'female'
    • </ol> 
    ##table() 함수 : 요인객체에 빈도표 작성
table(f.1)

    f.1
  male female 
     6      0 

    f.2 <- factor(c("white","black","white","white","white","white"))

    (t <- table(f.1,f.2)) #table = t

            f.2
f.1      black white
  male       1     5
  female     0     0

    ##margin.table() :주변표 작성
margin.table(t, 1) #1은 행

    f.1
  male female 
     6      0 

    margin.table(t,2) #2는 열

    f.2
black white 
    1     5 

    ##prop .table(): 비율표 작성 
prop.table(t, 1)

            f.2
f.1          black     white
  male   0.1666667 0.8333333
  female                    

    prop.table(t, 2)

            f.2
f.1      black white
  male       1     1
  female     0     0

    # margin.table은 합, prop.table은 백분율

    prop.table(t)

            f.2
f.1          black     white
  male   0.1666667 0.8333333
  female 0.0000000 0.0000000

    ##matrix() 함수: 행렬 겍체 생성 
m <- matrix(c(1,2,3,4,5,6,7,8),2,4)

    m
    1357
    2468
     
    m <- matrix(c(22,33,44),1,3)

    m
    223344
     
    m[1,3]

    44

    m[1,]

    <ol class=list-inline> <li>22</li> <li>33</li> <li>44</li> </ol>

    m[1,-3]

    <ol class=list-inline> <li>22</li> <li>33</li> </ol>

    m[1,-2]

    <ol class=list-inline> <li>22</li> <li>44</li> </ol>

    ##array 함수 :배열 객체 생성 ,3차원 배열
a <- array(1:30, c(2,5,3))

    a

    <ol class=list-inline> <li>1</li> <li>2</li> <li>3</li> <li>4</li> <li>5</li> <li>6</li> <li>7</li> <li>8</li> <li>9</li> <li>10</li> <li>11</li> <li>12</li> <li>13</li> <li>14</li> <li>15</li> <li>16</li> <li>17</li> <li>18</li> <li>19</li> <li>20</li> <li>21</li> <li>22</li> <li>23</li> <li>24</li> <li>25</li> <li>26</li> <li>27</li> <li>28</li> <li>29</li> <li>30</li> </ol>

    #list는 서로 다른 유형의 객체들의 순서화된 모임

l <- list(id=c(1,2,3), name=c("nam","dk","wd"),score=c(70,80,90))
l
    $id
    <ol class=list-inline>
  • 1
  • 2
  • 3
    • </ol>
    $name
    <ol class=list-inline>
  • 'nam'
  • 'dk'
  • 'wd'
    • </ol>
    $score
    <ol class=list-inline>
  • 70
  • 80
  • 90
    • </ol> 
    l$name

    <ol class=list-inline> <li>‘nam’</li> <li>‘dk’</li> <li>‘wd’</li> </ol>

    l$score

    <ol class=list-inline> <li>70</li> <li>80</li> <li>90</li> </ol>

    l[3]

    $score
70
80
90

    l[[3]]

    <ol class=list-inline> <li>70</li> <li>80</li> <li>90</li> </ol>

    l[[2]]

    <ol class=list-inline> <li>‘nam’</li> <li>‘dk’</li> <li>‘wd’</li> </ol>

    l$name

    <ol class=list-inline> <li>‘nam’</li> <li>‘dk’</li> <li>‘wd’</li> </ol>

    unlist(l)

    <dl class=dl-horizontal> <dt>id1</dt> <dd>‘1’</dd> <dt>id2</dt> <dd>‘2’</dd> <dt>id3</dt> <dd>‘3’</dd> <dt>name1</dt> <dd>‘nam’</dd> <dt>name2</dt> <dd>‘dk’</dd> <dt>name3</dt> <dd>‘wd’</dd> <dt>score1</dt> <dd>‘70’</dd> <dt>score2</dt> <dd>‘80’</dd> <dt>score3</dt> <dd>‘90’</dd> </dl>

    #data.frame() 함수: 데이터프레임 객체 생성
d <- data.frame(id=c(1,2,3),name=c("kim","dd","qq"),score=c(11,22,33))
d
    idnamescore
    1 kim11
    2 dd 22
    3 qq 33 
    d$id

    <ol class=list-inline> <li>1</li> <li>2</li> <li>3</li> </ol>

    d$name

    <ol class=list-inline> <li>kim</li> <li>dd</li> <li>qq</li> </ol>

    <summary style=display:list-item;cursor:pointer> Levels: </summary> <ol class=list-inline>
  • 'dd'
  • 'kim'
  • 'qq'
    • </ol> 
    d$score

    <ol class=list-inline> <li>11</li> <li>22</li> <li>33</li> </ol>

    d[2,3]

    22

    d[1,]
    idnamescore
    1 kim11 
    d[,1]

    <ol class=list-inline> <li>1</li> <li>2</li> <li>3</li> </ol>

    d[d$score >= 20,] # ,을 꼭 필요로 한다
    idnamescore
    22 dd22
    33 qq33
     
    d$name=="kim"

    <ol class=list-inline> <li>TRUE</li> <li>FALSE</li> <li>FALSE</li> </ol>

    d[d$name=="kim",]
    idnamescore
    1 kim11 
    d$name=="dd"

    <ol class=list-inline> <li>FALSE</li> <li>TRUE</li> <li>FALSE</li> </ol>

    d[d$name=="dd",]
    idnamescore
    22 dd22
     
    d[d$name=="dd","score"]

    22

    d[d$name=="dd","id"]

    2

    d[d$name=="dd",c("id","score")]
    idscore
    22 22
     
    names(d)

    <ol class=list-inline> <li>‘id’</li> <li>‘name’</li> <li>‘score’</li> </ol>

    names(d)[3]<- "total"

    d
    idnametotal
    1 kim11
    2 dd 22
    3 qq 33 
    names(d)

    'id'
'name' 
'total' 

    names(d)[1] <- "num"

    d
    numnametotal
    1 kim11
    2 dd 22
    3 qq 33