Am 18.04.2017 um 13:51 schrieb Bald Eagle:
> It works just fine in POV-Ray, I'm just wondering what's getting buggered up in> Excel, or if I'm having an extended "senior moment"
As Scott just pointed out, Excel has `ATAN2(X;Y)`, while virtually all
proper programming languages have `atan2(y,x)`.
