How to substitute NA by 0 in 20 columns?
I want to substitute NA by 0 in 20 columns. I found this approach for 2 columns, however I guess it's not optimal if the number of columns is 20. Is there any alternative and more compact solution? mydata[,c("a", "c")] <- apply(mydata[,c("a","c")], 2, function(x){replace(x, is.na(x), 0)}) UPDATE: For simplicity lets take this data with 8 columns and substitute NAs in columns b, c, e, f and d a b c d e f g d 1 NA NA 2 3 4 7 6 2 g 3 NA 4 5 4 Y 3 r 4 4 NA t 5 5 The result must be this one: a b c d e f g d 1 0 0 2 3 4 7 6 2 g 3 NA 4 5 4 Y 3 r 4 4 0 t 5 5 We can use NAer from qdap to convert the NA