hamilton_filter: Clarify the API

[rht]

Aside, the docstring also has contradictory content:

[p] Must be greater than h.

and

e.g. For quarterly data, h = 8 and p = 4 are recommended.

As such, I haven't added a check to ensure that p > h.

[pep8speaks]

Hello @rht! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

There are currently no PEP 8 issues detected in this Pull Request. Cheers! 🍻

Comment last updated at 2022-06-08 04:21:06 UTC

[coveralls]

Coverage decreased (-0.001%) to 95.047% when pulling 1d296fc on rht:hamilton_filter into 393c8c3 on QuantEcon:master.

[mmcky]

@Shunsuke-Hori would you have time to review this?

thanks @rht for the PR.

[Shunsuke-Hori]

Aside, the docstring also has contradictory content:

[p] Must be greater than h.

and

e.g. For quarterly data, h = 8 and p = 4 are recommended.

As such, I haven't added a check to ensure that p > h.

I don't quite remember why I wrote so... Perhaps I misunderstood h with another parameter when I initially wrote the code and forgot to delete the requirement when I push it here. In any case, p > h is not required.

[Shunsuke-Hori]

I created another PR #637 for the fix of the doc

[Shunsuke-Hori]

I made a very small comment, but other than that, it looks good to me.

[mmcky]

thanks @Shunsuke-Hori and @rht