DEP: Alias hanning as an explanatory function of hann

[endolith]

So there aren't duplicate help pages misleading people into thinking
that they're subtly different.

As in #228 (comment)

[endolith]

I don't understand the build errors.

Exception occurred:
File "/home/ubuntu/scipy/build/testenv/lib/python2.7/site-packages/scipy/signal/init.py", line 345, in deco
raise RuntimeError('dev error: badly formatted doc')
RuntimeError: dev error: badly formatted doc

:/

[pv]

Looking into the last file in the traceback probably clarifies the issue.

[WarrenWeckesser]

Missing return statement. This line should be

return hann(*args, **kwargs)

[endolith]

derp. I'll fix that.

[WarrenWeckesser]

From the discussion in #228, it looks like hanning needs a complete docstring. It was suggested there that some sort of decorator for aliases be created, but in the meantime, the docstring for hanning could be copied from hann, with an additional note added at the top stating that it is an alias for hann.

[endolith]

the docstring for hanning could be copied from hann, with an additional note added at the top stating that it is an alias for hann.

Ok I'll do that for now.

[endolith]

(Or this could just wait until #8319)

[endolith]

I changed it to use numpy.deprecate instead:

@np.deprecate(new_name='hann')
def hanning(*args, **kwargs):
    return hann(*args, **kwargs)

Now it's being blocked by deco again.

@larsoner it looks like you create the deco function in #7900, do you have an opinion on it blocking these aliases? It's probably a good idea to make PRs fail if function docstrings don't have Parameters sections, but in the case of aliases I think it's ok.

[pv]

You can just remove hanning from deprecated_windows since np.deprecated already adds the deprecation warning. The new_name however likely should be the full name, scipy.signal.windows.hann.

[endolith]

@pv ok I did that.

https://5506-1460385-gh.circle-artifacts.com/0/home/ubuntu/scipy/doc/build/html-scipyorg/generated/scipy.signal.windows.hanning.html

https://5506-1460385-gh.circle-artifacts.com/0/home/ubuntu/scipy/doc/build/html-scipyorg/generated/scipy.signal.windows.hann.html