2020 1 30
1 2
2 2
3 2
3.1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4 4
4.1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4.2 R mode . . . . . . . . . . . . . . . . . . . . . . . . 4
4.3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4.4 NULL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4.5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5 6
5.1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
6 7
6.1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
6.2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
6.3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6.4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
6.5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
7 11
7.1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
8 11
1

2
1
•
•
• logical, numeric, complex, character
•
•
•
2
R #
#
> #################
> ##
> #################
> cat("ABC") #
ABC
3
> 3 * 4
[1] 12
> 3 * 4 + 2
[1] 14
> 3 * (4 + 2)
[1] 18
> 3/4
[1] 0.75
> -5 / -6
[1] 0.8333333
> (-5)/(-6)
[1] 0.8333333
2
I 2

3.1 2
> 2^3 # ^
[1] 8
> 2**3 # * 2
[1] 8
> 2^3*4 #
[1] 32
> 2^(3*4)
[1] 4096
> 2**3*4 # ** *
[1] 32
> 2**(3*4)
[1] 4096
> sqrt(2)
[1] 1.414214
> 2^(1/2)
[1] 1.414214
log(2) log(2)= loge 2 = ln 2
log(100,10)= log10 100
> log(2)
[1] 0.6931472
> log(100, 10)
[1] 2
> exp(1)
[1] 2.718282
> exp(0.6931472)
[1] 2
absolute values
> abs(-0.2)
[1] 0.2
> abs(0.2)
[1] 0.2
3.1
•
•
•
I 3

2
•
4
4.1
•
• 0 1 0 1
•
=⇒
• R mode
4.2 R mode
• logical : TRUE FALSE
T F
• numeric : R numeric
• complex : i
• character :
mode() mode mode()
> mode(TRUE)
[1] "logical"
> mode(FALSE)
[1] "logical"
> mode(pi) # pi
[1] "numeric"
> mode(2.0)
[1] "numeric"
> mode(2)
[1] "numeric"
> mode(2+2i)
[1] "complex"
> mode(" ")
[1] "character"
I 4

4.3 2
is. ()
> is.character(" ")
[1] TRUE
> is.numeric(" ")
[1] FALSE
> is.numeric(3.14)
[1] TRUE
> is.numeric(pi)
[1] TRUE
> is.logical(FALSE)
[1] TRUE
> is.logical(1)
[1] FALSE
4.3
’<-’
> x <- 3 # x 3
> x #
[1] 3
> is.numeric(x) # x
[1] TRUE
> y <- " "
> y
[1] " "
> is.character(y)
[1] TRUE
> is.numeric(x)
[1] TRUE
> mode(y)
[1] "character"
4.4 NULL
• 0 1 0
NULL
• R NULL
> x <- NULL # NULL
> x # x NULL
NULL
I 5

4.5 2
> is.numeric(x)
[1] FALSE
> is.null(x) # NULL
[1] TRUE
> mode(x) # NULL mode "NULL"
[1] "NULL"
> x <- FALSE # x
> is.null(x) # NULL
[1] FALSE
> is.logical(x)
[1] TRUE
> mode(x)
[1] "logical"
4.5
•
• mode
•
• logical numeric complex character
• mode()
• is. ()
•
• NULL
5
1
R
• vector : mode 1
1
• matrix : mode 2
• array : mode n
I 6

5.1 2
• list :
• data.frame : 2
mode
3
5.1
•
•
• vector, matrix, array, list
•
6
6.1
c() c() combine 1
> c(1, 2, 3, 4) #
[1] 1 2 3 4
> c(1, 2, c(3, 4)) #
[1] 1 2 3 4
> v <- c("a", "b", "c") #
> v # v
[1] "a" "b" "c"
> c(v, v, c(1, 2, 3)) #
[1] "a" "b" "c" "a" "b" "c" "1" "2" "3"
6.2
replicate rep(x, times) x times
I 7

6.3 2
> rep(1, 5)
[1] 1 1 1 1 1
> rep(" ", 3)
[1] " " " " " "
> rep(TRUE, 3)
[1] TRUE TRUE TRUE
> rep(c(1, 2), 3) #
[1] 1 2 1 2 1 2
rep()
sequence seq(from, to, by) from to by
by 1
> seq(1, 10)
[1] 1 2 3 4 5 6 7 8 9 10
> seq(1, 10, 2) # 2
[1] 1 3 5 7 9
> seq(10, 1)
[1] 10 9 8 7 6 5 4 3 2 1
> seq(10, 1, -2)
[1] 10 8 6 4 2
6.3
[1]
> seq(1, 50)
[1] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
[28] 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
> 1
[1] 1
1 1
[]
> x <- 1:10
> x
[1] 1 2 3 4 5 6 7 8 9 10
> x[1]
[1] 1
> x[2]
[1] 2
I 8

6.4 2
> x[10]
[1] 10
[]
> days <- c(" ", " ", " ", " ", " ", " ", " ")
> days
[1] " " " " " " " " " " " " " "
> days[3]
[1] " "
> days[c(1, 2, 3)]
[1] " " " " " "
> days[1:3]
[1] " " " " " "
> days[seq(2, 7, 2)] # 2 1 1
[1] " " " " " "
> days[-3] # 3
[1] " " " " " " " " " " " "
> days[-1:-3] # 1 3
[1] " " " " " " " "
> days[-seq(2, 7, 2)] # seq(2,7,2) c(2,4,6)
[1] " " " " " " " "
length()
> length(days)
[1] 7
> length(x)
[1] 10
6.4
1 1 R
1 50 :
1:50 seq(1,50) 1
> x <- 1:50 # seq(1, 50)
> x
[1] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
I 9

6.5 2
[28] 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
> y <- 50:1 # seq(50, 1)
> y
[1] 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24
[28] 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
> x * 2 # 2
[1] 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40
[21] 42 44 46 48 50 52 54 56 58 60 62 64 66 68 70 72 74 76 78 80
[41] 82 84 86 88 90 92 94 96 98 100
> x / 2 # 2
[1] 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0
[17] 8.5 9.0 9.5 10.0 10.5 11.0 11.5 12.0 12.5 13.0 13.5 14.0 14.5 15.0 15.5 16.0
[33] 16.5 17.0 17.5 18.0 18.5 19.0 19.5 20.0 20.5 21.0 21.5 22.0 22.5 23.0 23.5 24.0
[49] 24.5 25.0
> x + 100 # 100
[1] 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120
[21] 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140
[41] 141 142 143 144 145 146 147 148 149 150
> x + y # x y
[1] 51 51 51 51 51 51 51 51 51 51 51 51 51 51 51 51 51 51 51 51 51 51 51 51 51 51 51
[28] 51 51 51 51 51 51 51 51 51 51 51 51 51 51 51 51 51 51 51 51 51 51 51
> log(1:5) # log(c(1, 2, 3, 4, 5)) log
[1] 0.0000000 0.6931472 1.0986123 1.3862944 1.6094379
> (1:5)^2 # c(1, 2, 3, 4, 5)^2
[1] 1 4 9 16 25
(1:5)^2 1:5
2 1:5^2 1 52
= 25
> 1:5^2 # 1:25
[1] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
6.5
• :
• c() rep() seq()
•
• length()
I 10

2
7
rep()
> help(rep)
standard deviation help.search()
> help.serach("standard deviation")
stats::sd stats
sd() help(sd)
R
source
R source
help.search()
7.1
• help()
• help.search()
•
• sd()
8
(1) 2, 4, 6, 8, 10 10
[1] 2 4 6 8 10 2 4 6 8 10 2 4 6 8 10 2 4 6 8 10 2 4 6 8 10
[26] 2 4 6 8 10 2 4 6 8 10 2 4 6 8 10 2 4 6 8 10 2 4 6 8 10
> rep(seq(2, 10, 2), 10)
(2) 2, 4, 6, 8, 10 100
I 11

2
> rep(seq(2, 10, 2), 100)
(3) sd() 2
> sd(rep(seq(2, 10, 2), 10))
[1] 2.857143
> sd(rep(seq(2, 10, 2), 100))
[1] 2.83126
I 12