Add Symmetry plot method

[harripj]

Description of the change

As discussed in #303 and #171, it would be a good idea to add a plot method to Symmetry to display symmetry elements in the crystal reference frame under the stereographic projection.

Closes #171.

Progress of the PR

• Docstrings for all functions
• Unit tests with pytest for all lines
• Clean code style by running black via pre-commit

Minimal example of the bug fix or new feature

>>> from orix.quaternion import symmetry
>>> symmetry.O.plot()

For reviewers

• The PR title is short, concise, and will make sense 1 year later.
• New functions are imported in corresponding __init__.py.
• New features, API changes, and deprecations are mentioned in the
  unreleased section in CHANGELOG.rst.

[hakonanes]

Very helpful and nice visualization of symmetry operations! All requests and comments are related to documentation and tests.

Should add plot to the list of Symmetry methods below from_generators in the reference.

[hakonanes]

Seems like GitHub has submitted all my comments twice. I suggest to leave the extra comments, in case both are deleted when one is deleted...

EDIT: Seems like its only on my end, since the extra comments are labeled "Pending".

EDIT2: This is just the case for some of them it seems.

[harripj]

Doc build error looks like it is part of jinja2 or nbconvert and is being experienced elsewhere recently: sphinx-doc/sphinx#10289

[harripj]

Doc build error looks like it is part of jinja2 or nbconvert and is being experienced elsewhere recently: sphinx-doc/sphinx#10289

Looks like a fairly minor fix. I suggest we wait until nbconvert pushes the patch which will hopefully sort everything from our side without change, An alternative is to pin jinja2 to 3.0 in requirements, but it seems that like this will be cleared up pretty quickly.

[hakonanes]

I suggest we wait until nbconvert pushes the patch which will hopefully sort everything from our side without change

I agree. Checked the notebook locally, just had one important comment.

[hakonanes]

After the notebook change, I have a final suggestion: could you update the locations of other relevant packages references in conf.py

from

    "h5py": ("http://docs.h5py.org/en/stable/", None),
    "matplotlib": ("https://matplotlib.org", None),
    "numpy": ("https://docs.scipy.org/doc/numpy", None),
    "scipy": ("https://docs.scipy.org/doc/scipy/reference", None),

to

    "h5py": ("https://docs.h5py.org/en/stable", None),
    "matplotlib": ("https://matplotlib.org/stable", None),
    "numpy": ("https://numpy.org/doc/stable", None),
    "scipy": ("https://docs.scipy.org/doc/scipy", None),

Sphinx tells us nicely that they have changed when running make html.

[harripj]

Doc build error looks like it is part of jinja2 or nbconvert and is being experienced elsewhere recently: sphinx-doc/sphinx#10289

Looks like a fairly minor fix. I suggest we wait until nbconvert pushes the patch which will hopefully sort everything from our side without change, An alternative is to pin jinja2 to 3.0 in requirements, but it seems that like this will be cleared up pretty quickly.

NB this is the PR in question jupyter/nbconvert#1737.

[harripj]

NB this is the PR in question jupyter/nbconvert#1737.

This appears to have been fixed.

[hakonanes]

This PR can now use reprojection functionality of vectors on the other hemisphere!

[hakonanes]

Just ping me whenever this is ready for review.

[harripj]

@hakonanes I think this is good for review. I will look at #308 now too.

[hakonanes]

This is a very good way to visualize symmetry operations; I'm sure I'll use it many times!

I've suggested an insignificant change to the user guide notebook. Performing the change isn't required to merge, but I think it shows the user a slightly simpler way to reflect a vector about the projection plane.

[pc494]

This looks good, assuming the tests green light. I'll let @hakonanes merge.