Non-smooth functions with gradient defined

[hakkelt]

While making changes for #152 , I realized that there are functions that have gradient! implemented, but neither is_smooth nor is_locally_smooth is true for them. Why is that? Wouldn't they need a property function that signals that they have gradients defined for a part of their domain?

• DistL2
• ElasticNet
• NormL2
• NormLinf
• SumPositive

I ask this out of curiosity, not because I really need such functionality.

[lostella]

I guess that’s the result of overloading “gradient” with “an element of the subdifferential” really. Something one could re-think, of course.

[hakkelt]

Thanks, that was my guess, too.