How do I sum the values of columns in several tables if tables have different lengths?

Question

Alright, this should be an easy one but I\'m looking for a solution that\'s as fast as possible.

Let\'s say I have 3 tables (the number of tables will be much larger

Answer 1

you can try this

df <- rbind(as.matrix(tab1), as.matrix(tab2), as.matrix(tab3))
aggregate(df, by=list(row.names(df)), FUN=sum)
  Group.1 V1
1       1  7
2       2  3
3       3  4
4       4  3
5       5  1