hw1

자료 1의 Q2

rep("noun",10)

##  [1] "noun" "noun" "noun" "noun" "noun" "noun" "noun" "noun" "noun" "noun"

rep("verb",20)

##  [1] "verb" "verb" "verb" "verb" "verb" "verb" "verb" "verb" "verb" "verb"
## [11] "verb" "verb" "verb" "verb" "verb" "verb" "verb" "verb" "verb" "verb"

x <- rep("noun",10)
y <- rep("verb",20)
c(x,y)

##  [1] "noun" "noun" "noun" "noun" "noun" "noun" "noun" "noun" "noun" "noun"
## [11] "verb" "verb" "verb" "verb" "verb" "verb" "verb" "verb" "verb" "verb"
## [21] "verb" "verb" "verb" "verb" "verb" "verb" "verb" "verb" "verb" "verb"

자료 1의 Q3

seq(1,10)

##  [1]  1  2  3  4  5  6  7  8  9 10

자료 2의 두번째 연습문제 세트 (%in% 과 match 나오는 거)

Q1.

1:10 %in% c(1,3,5,9)

##  [1]  TRUE FALSE  TRUE FALSE  TRUE FALSE FALSE FALSE  TRUE FALSE

z <- 1:10
o <- c(1,3,5,9)
z %in% o

##  [1]  TRUE FALSE  TRUE FALSE  TRUE FALSE FALSE FALSE  TRUE FALSE

z[z %in% o]

## [1] 1 3 5 9

Q2.

sym <- c("c", "ab", "B", "bba", "NA", "@", "bla", "Ba", "%")
letters

##  [1] "a" "b" "c" "d" "e" "f" "g" "h" "i" "j" "k" "l" "m" "n" "o" "p" "q" "r" "s"
## [20] "t" "u" "v" "w" "x" "y" "z"

LETTERS

##  [1] "A" "B" "C" "D" "E" "F" "G" "H" "I" "J" "K" "L" "M" "N" "O" "P" "Q" "R" "S"
## [20] "T" "U" "V" "W" "X" "Y" "Z"

sym %in% LETTERS

## [1] FALSE FALSE  TRUE FALSE FALSE FALSE FALSE FALSE FALSE

sym[sym %in% LETTERS]

## [1] "B"

Q3.

a <- c("dog", "cat", "duck")
b <- c("dog", "puppy", "pet", "animal")
match(a,b)

## [1]  1 NA NA

match(b,a)

## [1]  1 NA NA NA

a[a %in% b]

## [1] "dog"