Set NA to 0 in R

Question

After merging a dataframe with another im left with random NA\'s for the occasional row. I\'d like to set these NA\'s to 0 so I can perform calculations with them.

Answer 1

To add to James's example, it seems you always have to create an intermediate when performing calculations on NA-containing data frames.

For instance, adding two columns (A and B) together from a data frame dfr:

temp.df <- data.frame(dfr) # copy the original
temp.df[is.na(temp.df)] <- 0
dfr$C <- temp.df$A + temp.df$B # or any other calculation
remove('temp.df')

When I do this I throw away the intermediate afterwards with remove/rm.