I have two data (Z and E) sets with a many-to-many relationship and
need some help on how to do the final stage of the merge. This is the
setup
Dataset Z
Z E V1
--------------
z1 e1 12
z2 e1 14
z3 e2 16
Dataset E
E Z V2
----------------
e1 . 6
e2 . 7
e3 z2 8
The setup ensures that there is at least one Z mapped to each E and
vice versa. Merging them I get:
z1 e1 12 6
z2 e1 14 6
z2 e3 14 8
z3 e2 16 8
Now I need to roll aggregate the observations into unique
observations. In this example I should end up with:
z3e2 16 7
zXeX 26 14
where the z3e2 is unique from the merged dataset but zXeX is a sum of
e1 and e3 as well as z1 and z2. My question to all of you is, how do I
code this last step? I can identify which Zs and Es require "rollup"
(because there are multiple obsevations). I can also identify
"overlapping rollups" (case z2 e1 above where both the Z and E in the
observation requires rollup).
While I can probably figure this out myself given some time I figure I
should see if anyone has an obvious solution.
Thanks,
Fredrik
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