Question

I have a data frame which has some rows with NA entries, I want to find the index of the row and the column at which the entry is NA. I am looping in a nested fashion to do that, and that is taking too long. Is there a quicker way to do it? Thanks.

Answer 1

set.seed(123)
dfrm <- data.frame(a=sample(c(1:5, NA), 25,T), b=sample(c(letters,NA), 25,rep=T)
which(is.na(dfrm), arr.ind=TRUE)
      row col
 [1,]   4   1
 [2,]   5   1
 [3,]   8   1
 [4,]  11   1
 [5,]  16   1
 [6,]  20   1
 [7,]  21   1
 [8,]  24   1
 [9,]   6   2