내용 |
x <- 100
y <- 200
x + y
R.version
iris
# 1. 도움말
?iris
help("iris")
??iris
help.search("iris")
library(help="stats")
methods(as)
args(data)
args(lm)
?lm
attributes(iris)
example(mean)
?mean
# 주석입니다.
R.version
# 2. 패키지
install.packages("arules")
library(arules)
iris
a
detach("package:datasets", unload=TRUE)
data(iris)
iris
library(datasets)
data(iris)
iris
# 3. 변수
# 숫자, 알파벳, _, . 로 구성
# 시작 문자는 알파벳 또는 .으로 시작
# .은 히든변수
# <-, ->, <<-, ->>, =
result <- 0
add <- function(a, b) {
return (a + b)
}
add(1,2)
result <- add(1,2)
result2 <- 0
add2 <- function(a, b) {
result2 <<- a + b # 전역변수에 값 할당
return (result)
}
add2(1,2)
result2
ls()
ls.str()
rm(x)
ls()
rm(y)
ls()
?rm
ls()
rm(list=ls())
ls()
# 4. 출력
x <- 3
y <- 5
x+y
z <- x + y
z
rm(z)
(z <- x + y)
print(z)
cat(1,2,3,4)
paste("Hello", "World")
paste("Hello", "World", sep=",")
paste0("Hello", "World")
month.name
paste0(1:12, c("st", "nd", "rd", rep("th", 9)))
nth <- paste0(1:12, c("st", "nd", "rd", rep("th", 9)))
month.name
# January: 1st; February: 2nd;
paste(month.name, nth, sep=": ")
paste(month.name, nth, sep=": ", collapse="; ")
# 2장. R 데이터 종류 및 구조
a <- "Hello"
is.character(a)
a <- 10
is.character(a)
a <- "Hello"
b <- 10
is.numeric(b)
c <- TRUE
is.logical(c)
class(a)
class(b)
class(c)
str(a)
str(iris)
d <- c(2,4,NA,6) #vector
d
is.na(d)
is.na(d[3])
complete.cases(d)
mean(d)
mean(d, na.rm=TRUE)
mean(na.omit(d))
# factor, 범주형 변수
gender <- c("남", "여", "남", "남", "여")
gender
as.factor(gender)
gender <- factor(c("남", "여", "남", "남", "여"), levels=c("남", "여"))
gender
nlevels(gender)
levels(gender)
class(gender)
str(gender)
gender <- factor(c("남", "여", "남", "남", "여"),
levels=c("남", "여"),
ordered=TRUE)
gender
# vector, c()
data <- c(1,2,3)
data
NROW(data)
names(data)
names(data) <- c("열1", "열2", "열3")
names(data)
data["열1"]
data[1]
data[-1]
data[c(1,3)]
data[data>2]
data[c(FALSE, FALSE, TRUE)]
data[c(TRUE, FALSE, TRUE)]
a <- c(1,2,3)
class(a)
a <- numeric(3)
a[1] <- 1
a[2] <- 2
a[3] <- 3
class(a)
a
b <- c("Hello", "World")
b
c <- c(TRUE, FALSE, TRUE, FALSE)
(z <- c(a,b,c))
(z <- c(a,c))
a
c(a, c(4,5,6))
append(a, c(4,5,6))
a <- 1:6 #c(1,2,3,4,5,6)
b <- c(2,4,6,8,10,12)
union(a,b)
intersect(a,b)
setdiff(a,b)
a
b
a + b
seq(1, 10)
seq(0, 1)
seq(1, 10, by=2)
seq(0, 1, length.out=11)
seq(10)
1:3
1:10
rep(1:4, 2)
rep(1:4, each=2)
rep(1:4, c(4,3,1,3))
rep(1:4, each=2, length=7)
rep(1:4, each=2, times=3)
?rep
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