Quote Originally Posted by DonkeyOte View Post
It's not clear where "the matrix" is stored... for sake of demo, let's assume:

Target depth: E17

Matrix: A20:M46

where:

A21:A46: Lettered Pressure Groups A:Z
B20:M20: Depths (35 to 140)


H17: =LOOKUP(9.99E+307,INDEX($B$21:$M$46,0,$F$17),$A$21:$A$46)
associated pressure group with max time for given depth


I wasn't sure what you meant by "next time up" so I've assumed you want the first time that is >= target time
I've got the bulk of the suggested formulae to work, but the one left in the quote only returns a pressure group of Z, not the pressure group related to the maximum time for a given column.

BTW, I'm trying to dissect what you've done (because it worked!), but I can't seem to fix the one issue. Thanks for the help. I'd not likely have figured it out on my own.