Problem description & analysis:
An Excel table has two columns of numbers, and there are duplicates in a column:
Task: First remove duplicates from the columns and then compute their intersection:
Solution:
Use SPL XLL to do this:
=spl("=[?1,?2].isect(~.group().select(~.len()==1).conj())",A1:A5,B1:B4)
As shown in the picture below:
Explanation:
isect()computes the intersection. group() groups data but does not perform aggregation. select() performs filtering operation; ~ is the current member.