class ScaledRotation(Affine2DBase):
    """
    A transformation that applies offset and direction
    based on *trans_shift*.
    """
    def __init__(self, theta, trans_shift, is_radial):
        super().__init__()
        self._theta = theta
        self._trans_shift = trans_shift
        self._is_radial = is_radial
        self._mtx = np.identity(3)

    def get_matrix(self):
        if self._invalid:
            transformed_coords = self._trans_shift.transform([[self._theta, 0]])[0]
            adjusted_theta = transformed_coords[0]
            if self._is_radial:
                adjusted_theta -= np.pi / 2
            rotation = mtransforms.Affine2D().rotate(adjusted_theta)
            self._mtx[:2, :2] = rotation.get_matrix()[:2, :2]
        return self._mtx

if self.name == 'polar':
            trans_shift = self.transShift
            for axis in caplines:
                for l in caplines[axis]:
                    # Rotate caps to be perpendicular to the error bars
                    for theta, r in zip(l.get_xdata(), l.get_ydata()):
                        rotation = ScaledRotation(
                            theta=theta,
                            trans_shift=trans_shift,
                            is_radial=(axis == 'y')
                        )
                        ms = mmarkers.MarkerStyle(marker=marker,
                                                  transform=rotation)
                        self.add_line(mlines.Line2D([theta], [r], marker=ms,
                                                    **eb_cap_style))

class ScaledRotation(Affine2DBase):
    def __init__(self, theta: float, trans_shift: Transform, is_radial: bool) -> None: ...
    def get_matrix(self) -> np.ndarray: ...

@pytest.mark.parametrize("order", ["before", "after"])
@image_comparison(baseline_images=['polar_errorbar'], remove_text=True,
                  extensions=['png'], style='mpl20')
def test_polar_errorbar(order):
    theta = np.arange(0, 2 * np.pi, np.pi / 8)
    r = theta / np.pi / 2 + 0.5
    fig = plt.figure(figsize=(5, 5))
    ax = fig.add_subplot(projection='polar')
    if order == "before":
        ax.set_theta_zero_location("N")
        ax.set_theta_direction(-1)
        ax.errorbar(theta, r, xerr=0.1, yerr=0.1, capsize=7, fmt="o", c="seagreen")
    else:
        ax.errorbar(theta, r, xerr=0.1, yerr=0.1, capsize=7, fmt="o", c="seagreen")
        ax.set_theta_zero_location("N")
        ax.set_theta_direction(-1)

import matplotlib.pyplot as plt
import numpy as np
theta = np.arange(0, 2 * np.pi, np.pi / 8)
r = theta / np.pi / 2 + 0.5
fig = plt.figure(figsize=(5, 5))
ax = fig.add_subplot(projection='polar')
ax.errorbar(theta, r, xerr=0.1, yerr=0.1, capsize=7, fmt="o", c="seagreen")
ax.set_theta_zero_location("SW")
ax.set_theta_direction(-1)
ax.set_yticklabels([])
plt.show()

import matplotlib.pyplot as plt
import numpy as np
theta = np.arange(0, 2 * np.pi, np.pi / 8)
r = theta / np.pi / 2 + 0.5
fig = plt.figure(figsize=(5, 5))
ax = fig.add_subplot(projection='polar')
ax.errorbar(theta, r, xerr=0.1, yerr=0.1, capsize=7, fmt="o", c="seagreen")
ax.set_theta_zero_location("NW")
ax.set_theta_direction(1)
ax.set_yticklabels([])
plt.show()