Sigmoid Kernel

Question

Sigmoid Kernel

John1911603424 opened this issue 6 years ago · 3 comments

John1911603424 commented 6 years ago

Hi,do you know where sigmoid kernel is? I didn't find it.

John1911603424 commented 6 years ago

Thanks.

Answer 1 · 2018-09-02T10:54:39.000Z

We have not implemented it.

Answer 2 · 2018-09-03T03:56:07.000Z

a longer reply: in our personal experience, the sigmoid kernel rarely makes sense. It is slightly difficult to work with because positive-definiteness of the kernel is not guaranteed. Also as a model the sigmoid kernel has super weird behaviour.

See here:

https://cloud.githubusercontent.com/assets/5733246/18803657/6883294a-81c8-11e6-8950-6989e765966a.png