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

I just ate a bug because of that inconsistency

  • $\begingroup$ UndirectedEdge has the same problem. $\endgroup$
    – Murta
    Aug 24, 2013 at 12:47

1 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.


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