R merge two dataframes by rows with some similar but also different columns

aa <- data.frame(a= c(1,1,2,3,4), b = c(5,3,2,6,1))
bb <- data.frame(a= c(1,1,6,7,4), c = c(4,3,7,2,1))

I want to merge aa and bb by the rows, however, when I use the rbind() function, it gives me an error that "the numbers of columns of arguments do not match". The final format that I want keeps all the columns that are present in both data frame and fill them with zeros if one column does not exist in the other dataframe’s part. A sample output for the reproducible data would be as follows:

Thank you for your time!

>Solution :

You can use bind_rows from dplyr, it’s similar to rbind but any missing columns are filled with NA instead of throwing an error.

cc <- dplyr::bind_rows(aa, bb)
cc <- replace(cc, is.na(cc), 0)

   a b c
1  1 5 0
2  1 3 0
3  2 2 0
4  3 6 0
5  4 1 0
6  1 0 4
7  1 0 3
8  6 0 7
9  7 0 2
10 4 0 1