The following is what I have:
ID Year Score
1 1999 10
1 2000 11
1 2001 14
1 2002 22
2 2000 19
2 2001 17
2 2002 22
3 1998 10
3 1999 12
The following is what I would like to do:
ID Year Score Total
1 1999 10 10
1 2000 11 21
1 2001 14 35
1 2002 22 57
2 2000 19 19
2 2001 17 36
2 2002 22 48
3 1998 10 10
3 1999 12 22
The amount of years and the specific years vary for each Id.
I have a feeling that it's some advanced options in ddply but I have not been able to find the answer. I've also tried working with for/while loops but since these are dreadfully slow in R and my data-set is large, it's not working all that well.
Thanks in advance!