Error : arguments imply differing number of rows

Error : arguments imply differing number of rows

row 수 안맞음

> df <- data.frame( A=c(1,2,3,4), B=c(1,2,3,4,5,6))

Error in data.frame(A = c(1, 2, 3, 4), B = c(1, 2, 3, 4, 5, 6)) : 
  arguments imply differing number of rows: 4, 6

자동으로 맞춰서 row수 맞춤

> df <- data.frame( A=c(1,2,3), B=c(1,2,3,4,5,6))
> df <- data.frame( A=c(1,2), B=c(1,2,3,4,5,6))

NA

a <- c(1,2,NA)

[1]  1  2 NA

 NA 갯수 확인

sum(length(which(is.na(a))))

[1] 1

NA제거

a <- a[!is.na(a)]

[1] 1 2

a <- as.factor(c("A", "B", NA))

[1] A    B    <NA>
Levels: A B

a <- a[na.omit(a)]

[1] A B
Levels: A B