[BUG]: Shift box_aspect according to vertical_axis

[Illviljan]

PR summary

Make sure box_aspect stays the same for each axis when using set_box_aspect and vertical_axis is used.

import matplotlib.pyplot as plt
import numpy as np


x = np.array([0, 1, 2, 4])
y = np.array([5, 10])
z = np.array([100, 150, 200])
X, Y, Z = np.meshgrid(*[x, y, z], indexing="ij")
c = np.arange(0, X.size)

plt.figure()
for j, (a, e) in enumerate([(0, 0), (-60, 30)]):
    for i, vert_a in enumerate(["z", "y", "x"]):
        ax = plt.subplot(2, 3, j * 3 + 1 + i, projection="3d")
        pc = ax.scatter(X, Y, Z, c=c)
        ax.view_init(azim=a, elev=e, vertical_axis=vert_a)
        ax.set_title(f"azim={a}, elev={e}, vertical_axis='{vert_a}'")
        ax.set_xlabel("x")
        ax.set_ylabel("y")
        ax.set_zlabel("z")
        ax.set_box_aspect((1, 2, 3))

Before PR:

With PR:

PR checklist

• Closes [Bug]: class Axes3D.set_box_aspect() sets wrong aspect ratios when Axes3D.view_init( vertical_axis='y') is enabled. #24328
• Closes [Bug]: set_aspect incompatible with view_init #28052
• new and changed code is tested

[Illviljan]

Fixes set_aspect as well, since it uses set_box_aspect.

import numpy as np
import matplotlib.pyplot as plt
import mpl_toolkits.mplot3d as a3

plt.close('all')
fig = plt.figure()
ax = fig.add_subplot(111, projection='3d')
ax.view_init(vertical_axis='y')
ax.set_xlabel('X')
ax.set_ylabel('Y')
ax.set_xlabel('Z')
ax.axes.set_xlim3d(left=-1, right=3.5) 
ax.axes.set_ylim3d(bottom=0, top=10) 
ax.axes.set_zlim3d(bottom=-0.5, top=3.5) 
ax.set_aspect('equal')
    
def a(elemList):
    return np.array(elemList)

def drawTriangle(centre, size=1, color='y'):
    # A neuron is a triangle
    left = centre + a([- size / 2, - size / 2, 0])
    right = centre + a([size / 2, - size / 2, 0])
    top = centre + a([0, size / 2, 0])
    coords = a([left, top, right])
    tri = a3.art3d.Poly3DCollection([coords])
    tri.set_color(color)
    tri.set_edgecolor('k')
    ax.add_collection3d(tri)

for col in range(3):
    drawTriangle(a([col, 10, 0]))

With PR:

[scottshambaugh]

Thanks for fixing this as well! Two small notes, then I can approve the MR.

[scottshambaugh]

What's the reason for removing this line? I'm not totally clear where it comes into play (when redrawing somewhere?), but note that the 3D test coverage isn't amazing so we should understand where behavior is changing. I would make sure that the plots are behaving as expected when you manually rotate the view.

Should remove rather than comment out if it's unneeded

[Illviljan]

It never was in main. I was just testing different ideas here.

Conclusion here is that box_aspect has to be local, otherwise there will be a new vertical axis each click (or call to get_proj).

[scottshambaugh]

CI failure looks unrelated to me, good to merge with a second reviewer!

[scottshambaugh]

It looks like this needs a rebase to deconflict with your other MR that was just merged in.