Date: Fri, 27 Oct 2017 17:52:23 -0400 From: Marten van Kerkwijk
When using units, if `a` is not angular (or dimensionless), I don't see how one could write code in which your example wouldn't fail... But I may be missing something, since for your example one would just realize that cos(ka)+i sin(ka) = exp(ika), in which case the log is just ika and one can the whole complexity...
Sorry, I thought I replied to you but somehow it didn’t go through. Yes, that example was a bit contrived, but it was just an example where something like sin(x) can be meaningful even if x is dimensional (though you much more typically see these things with log or exp).