Repair solar_azimuth_analytical

[adriesse]

pvlib python pull request guidelines

Thank you for your contribution to pvlib python!

You may submit a pull request with your code at any stage of completion, however, before the code can be merged the following items must be addressed:

• Closes issue solarposition.solar_azimuth_analytical returns nan #420
• Fully tested. Added and/or modified tests to ensure correct behavior for all reasonable inputs. Tests must pass on the TravisCI and Appveyor testing services.
• Code quality and style is sufficient. Passes git diff upstream/master -u -- "*.py" | flake8 --diff and/or landscape.io linting service.
• New code is fully documented. Includes sphinx/numpydoc compliant docstrings and comments in the code where necessary.
• Updates entries to docs/sphinx/source/api.rst for API changes.
• Adds description and name entries in the appropriate docs/sphinx/source/whatsnew file for all changes.

Please don't hesitate to ask for help if you're unsure of how to accomplish any of the above. You may delete all of these instructions except for the list above.

Brief description of the problem and proposed solution (if not already fully described in the issue linked to above):

[wholmgren]

Thanks! I like the conservative approach of only modifying values that are known to be problematic.

It may be worthwhile to explicitly define the atol parameter, even if it's equal to the default.

Can you add a simple test function to pvlib/test/test_solarposition.py that would have failed without these changes? The code in your comment could work if you replace the print statements with assert not bad_azi.any(). The new test should include a comment along the lines of # GitHub issue 420 (I often forget to do this, but it does help future readers).

Finally, please add your name and a comment to the docs/sphinx/source/whatsnew/0.5.2.rst file.

[adriesse]

Hi Will, could you give some additional hints on the flake8 action item?

[wholmgren]

The command checks the changes that you've made for PEP8 style issues. landscape.io is supposed to do this for us, but it's been unreliable for awhile now. I haven't gotten around to setting up a new service. Stickler-CI is showing up in a few other projects that I follow, so maybe we'll try that.

In any case, for this pull request, flake8 will complain about how you've used whitespace to make the lines more similar. However, I don't have a problem with the formatting you're using, so no need to worry about it.

If you're still interested in pursuing it, you can read the forking and the pep8 sections in the pandas contributing guide:

http://pandas.pydata.org/pandas-docs/stable/contributing.html

The forking section shows how to add the "upstream remote" (the main pvlib repository). The pep8 section talks a little more about the flake8 command. Note that you'll need to run the diff against "upstream/master" rather than your local master.

[adriesse]

Ok, I'll learn about flake8 another time.
The latest whatsnew file I see is for 0.4.5. Which one of us starts a new one?

[wholmgren]

Your fork shows that you have the 0.5.2 whatsnew file https://github.com/adriesse/pvlib-python/blob/master/docs/sphinx/source/whatsnew/v0.5.2.rst

Maybe you're looking at a different local copy of the code?

[adriesse]

No, I see now that the file extension changed from txt to rst.

[wholmgren]

Looks good, thanks Anton!!

[mikofski]

pls change single quotes around #420 to backticks

[mikofski]

so cool, thanks Anton!