R colSums()

1 개요

R colSums()

• Form Column Sums

matrix

m <- matrix(1:6, nrow=3, ncol=2)
m
##      [,1] [,2]
## [1,]    1    4
## [2,]    2    5
## [3,]    3    6
colSums(m)
## [1]  6 15

data.frame

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

colSums(mydf)
## English    Math 
##     180     300

sapply(mydf, sum)
## English    Math 
##     180     300 

apply(mydf, 2, sum)
## English    Math 
##     180     300

2 같이 보기

• R sum()
• R apply()
• R sapply()
• R colMeans()
• R rowSums()
• R margin.table()

3 참고

• https://www.rdocumentation.org/packages/base/versions/3.6.1/topics/colSums