I am trying to use a Lookup function using vectors to do the following:
I have a date/value times series of river flows in a columnar format:
1978 1979 1980 ...
4/1 15 16 5
4/2 20 45 10
4/3 25 30 15

peak 25 45 15

etc...

I have computed the peak flow using the Max function and I want to be able
to lookup the date corresponding to the computed peak flow for each year. I
tried to use the LOOKUP function with vectors but I realized that it only
works when the list is sorted which is not the case in my dataset. Is there a
way around this ?

Thanks