R apply()

1 개요

R apply()

options(echo=TRUE)
x <- matrix(1:12,3,4)
x
apply(x,1,mean)
apply(x,2,mean)

mydf <- read.table( header=TRUE, stringsAsFactors=FALSE, text="
English Math
     30   60
     40   70
     50   80
     60   90
")
mydf
##   English Math
## 1      30   60
## 2      40   70
## 3      50   80
## 4      60   90

rowMeans(mydf)
## [1] 45 55 65 75
apply(mydf, 1, mean)
## [1] 45 55 65 75

colMeans(mydf)
## English    Math 
##      45      75 
sapply(mydf, mean)
## English    Math 
##      45      75 
apply(mydf, 2, mean)
## English    Math 
##      45      75

2 같이 보기

• R lapply()
• R tapply()
• R sapply()
• R sweep()
• R aggregate()
• R apply 패밀리
• R rowMeans()
• R colMeans()

3 참고

• https://www.rdocumentation.org/packages/base/versions/3.6.0/topics/apply