Having fun with NaNs and mixed units in matrices

[JKT]

I had matrices with mixed unit and NaNs in calculation and kept getting units errors. It was a surprise to me that NaN would grab the unit from the first matrix element. After realizing that I found a similar thread about same happening with 0 values. In that case it was solved with zero. Interestingly that doesn't show in the list of units and I couldn't find it in the help either.

Anyway, for my purposes to solutions seems possible: either moving the unit row to bottom or to utilize zero with the NaN:

There's no question here, but I do find the behaviour more than a little odd...

[Werner_E]

I agree that the behaviour is quite odd.

We can't find zero or Zero in the list of constants or units or anywhere else, nor can we read about them anything in the help.

PTC sure kows how to hide important informations! They mention zero and Zero in a pdf only, the Mathcad Prime Migration Guide (Chapter 2, Resolving Conversion Issues - Worksheet Calculation).
Can be accessed from within Prime -> "Ressources-References-Migration Guide".