DiracDelta attributes

Question

Is there any reason why DiracDelta isn't a NumericFunction but DiracComb is?

I just ate a bug because of that inconsistency

Answer 1

You're right, applying FullDefinition I see that DiracDelta lacks the NumericFunction attribute. And indeed, NumericQ[DiracComb[1]] yields True whereas NumericQ[DiracDelta[0]] doesn't.

Although I'm not sure why that difference exists, you may perhaps be able to get the desired result (you didn't say what your bug was) by setting SetAttributes[DiracDelta, NumericFunction]. At least it then allows you to work with the knowledge that NumericQ[DiracDelta[0]] is True.

Actually, maybe it would be more correct to remove the NumericFunction from both... depends on what you want, I guess.