Sum of two Columns of Data Frame with NA Values

Question

I have a data frame with some NA values. I need the sum of two of the columns. If a value is NA, I need to treat it as zero.

a  b c d
1  2 3 4
5 NA 7 8
         


        

Answer 1

dplyr solution, taken from here:

library(dplyr)
dat %>% 
    rowwise() %>% 
    mutate(e = sum(b, c, na.rm = TRUE))