Dataframes in a list; adding a new variable with name of dataframe

Question

I have a list of dataframes which I eventually want to merge while maintaining a record of their original dataframe name or list index. This will allow me to subset etc acro

Answer 1

names() could work it it had names, but you didn't give it any. It's an unnamed list. You will need ti use numeric indices:

> for(i in 1:length(mylist) ){ mylist[[i]] <- cbind(mylist[[i]], id=rep(i, nrow(mylist[[i]]) ) ) }
> mylist
[[1]]
  x  y id
1 1 11  1
2 2 12  1
3 3 13  1
4 4 14  1
5 5 15  1

[[2]]
  x  y id
1 1 11  2
2 2 12  2
3 3 13  2
4 4 14  2
5 5 15  2