interpolation: interpolating at a blank or NaN point should not return #VALUE!
Submitted by Frédéric Parrenin
Steps to reproduce
- A1=1, A2=2, B1=1, B2=2
- D1=interpolation(A1:A2,B1:B2,C1) => #VALUE!
- if you put C1=NaN, still #VALUE! This is problematic, since if you want to re-use a range encompassing D1 in a formula, it will always return #VALUE!. I would prefer a Blank or a NaN value.
Version: git master