R table()

1 개요

R table()

2 벡터

x <- c(3,1,4,1,5,2,6,5)
table(x)

table( c(3,1,4,1,5,2,6,5) )

table( c("a","b","b","c","c","c","d") )

3 데이터프레임 컬럼

table(iris$Species)

v <- c(1, 'hello', 1, 'world', 'hello')
table(v)

summary(warpbreaks)

table(warpbreaks$wool,warpbreaks$tension)

scores <- read.table( header=TRUE, stringsAsFactors=FALSE, text="
Class  Name variable value
    A Alice  English    90
    A   Bob  English    80
    B  Dave  English    60
    A Alice     Math    60
    B Carol     Math    80
    B  Dave     Math    90
")
table( scores$variable )

table( scores$value )

4 table()과 ddply()

library(plyr)
table(baseball[1:100,]$year)

ddply(baseball[1:100,], ~year, nrow)

ddply(baseball[1:100,], 'year', nrow)

ddply(baseball[1:100,], .(year), nrow)

5 같이 보기

• R xtabs()
• R ddply()
• R factor()
• R ftable()
• R unique()
• R is.table()
• R as.table()
• R tabulate()
• R summary()
• R prop.table()
• R addmargins()
• R margin.table()
• R 분할표
• R 그룹별 건수 구하기
• 함수 array_count_values()

6 참고

• https://www.rdocumentation.org/packages/base/versions/3.5.3/topics/table