Displaying 1 result from an estimated 1 matches for "tp4533125p4533169".
2012 Apr 04
2
Selecting obs within groups defined by 2 variables
Hello,
I am relatively new to R, and I am trying to select the last
observation within a group, where the group is defined by two
variables. One of the variables is a date.
In the below example, C3 varies within C2, which varies within C1. I
need to select the last observation in C3 for 4 groups (C1*C2): 1x,
1y, 2x, and 2y. In my real dataset, C2 is a date (mm/dd/yy)
C1 C2 C3
1 x 1
1