r column is not na code example

Example 1: if not na in r

which( !is.na(p), arr.ind=TRUE)

Example 2: if not na in r

> which( !is.na(p), arr.ind=TRUE)
     row col
[1,]   1   2
[2,]   1   3
[3,]   2   4
[4,]   4   5
[5,]   2   7