"""Original solution figure; tested with Python 3.14 and root pyproject dependencies. Write the opaque PNG basename in cwd, including when run from its _media mirror. """ from pathlib import Path import matplotlib matplotlib.use('Agg') import matplotlib.pyplot as plt import numpy as np fig, ax = plt.subplots(figsize=(5.3, 5.3), dpi=130, facecolor='white') t = np.linspace(0, 2*np.pi, 500) ax.plot(np.cos(t), -2*np.sin(t), color='#31688e', lw=2) ax.axhline(0, color='0.6', lw=.8) ax.axvline(0, color='0.6', lw=.8) for end, color in [((1, 0), '#d55e00'), ((0, -2), '#009e73')]: ax.annotate('', end, (0, 0), arrowprops=dict(arrowstyle='->', lw=2.5, color=color)) ax.annotate(r'$\omega t=0:\ (1,0)$', (1, 0), (.45, .6), fontsize=11, color='#d55e00') ax.annotate(r'$\omega t=\pi/2:\ (0,-2)$', (0, -2), (-1.45, -2.45), fontsize=11, color='#009e73') for a in [.4, 2.1, 3.7, 5.3]: ax.annotate('', (np.cos(a+.2), -2*np.sin(a+.2)), (np.cos(a), -2*np.sin(a)), arrowprops=dict(arrowstyle='->', color='#31688e', lw=1.8)) ax.set(xlim=(-1.65, 1.65), ylim=(-2.7, 2.65), xlabel=r'$\Psi_x$', ylabel=r'$\Psi_y$') ax.set_aspect('equal') ax.set_title('A = +2i; viewed from +z toward the source', fontsize=11) ax.spines[['top', 'right']].set_visible(False) fig.tight_layout() fig.savefig(Path(__file__).with_suffix('.png').name, facecolor='white', transparent=False) plt.close(fig)