Finding maximum value of one column (by group) and inserting value into another data frame in R

Question

All,

I was hoping someone could find a solution to an issue of mine that isn\'t necessarily causing headaches, but, as of right now, invites the possibility for huma

Answer 1

It sounds like you're just looking for aggregate:

> aggregate(cbind(x1, x2, x3, x4) ~ country1 + year, Data, max)
  country1 year x1 x2 x3 x4
1        B 1998 30 10 30  2
2        A 2000 95 90 25 90
3        C 2005 90 90  5 40

It's not very clear from your question how you want to proceed from there though....