Suggestions from reviewers

MischaMegens2 · MischaMegens2 · commit cdcc9d8bcb69 · 2024-06-03T11:32:14.000-07:00
- makes axes3d.Quaternion a private _Quaternion class
- shortens as_cardan_angles()
- adds two extra tests to test_axes3d::test_quaternion(): from_cardan_angles() should return a unit quaternion, and as_cardan_angles() should be insensitive to quaternion magnitude
- updates "mplot3d View Angles" documentation (the mouse can control both azimuth, elevation, and roll; and matlab does have a roll angle nowadays)
- put in a reference to quaternion multiplication using scalar and vector parts (wikipedia)
- rename class method that constructs a quaternion from two vectors to `rotate_from_to()`
- clarify docstring: "The quaternion for the shortest rotation from vector r1 to vector r2"
- issue warning when vectors are anti-parallel: "shortest rotation is ambiguous"
- construct a perpendicular vector for generic r2 == -r1
- add test case for anti-parallel vectors
- add test for the warning
- add reference to Ken Shoemake's arcball, in axes3d.py
- point out that angles are in radians, not degrees, in quaternion class docstrings
- in test_axes3d, add an import for axes3d._Quaternion, to avoid repetition
- add Quaternion conjugate(), and tests for it
- add Quaternion norm, and tests
- add Quaternion normalize(), and tests
- add Quaternion reciprocal(), and tests
- add Quaternion division, and tests
- add Quaternion rotate(vector), and a test
diff --git a/doc/api/toolkits/mplot3d/view_angles.rst b/doc/api/toolkits/mplot3d/view_angles.rst
@@ -12,17 +12,16 @@ The position of the viewport "camera" in a 3D plot is defined by three angles:
 points towards the center of the plot box volume. The angle direction is a
 common convention, and is shared with
 `PyVista <https://docs.pyvista.org/api/core/camera.html>`_ and
-`MATLAB <https://www.mathworks.com/help/matlab/ref/view.html>`_
-(though MATLAB lacks a roll angle). Note that a positive roll angle rotates the
+`MATLAB <https://www.mathworks.com/help/matlab/ref/view.html>`_. Note that a positive roll angle rotates the
 viewing plane clockwise, so the 3d axes will appear to rotate
 counter-clockwise.
 
 .. image:: /_static/mplot3d_view_angles.png
    :align: center
    :scale: 50
 
-Rotating the plot using the mouse will control only the azimuth and elevation,
-but all three angles can be set programmatically::
+Rotating the plot using the mouse will control azimuth, elevation,
+as well as roll, and all three angles can be set programmatically::
 
     import matplotlib.pyplot as plt
     ax = plt.figure().add_subplot(projection='3d')
