"""Original entry-game tree; Python 3.14.4, Matplotlib 3.10.7. Write the opaque PNG beside the current working directory's files. """ from pathlib import Path import matplotlib matplotlib.use("Agg") import matplotlib.pyplot as plt def main(): fig, ax = plt.subplots(figsize=(6, 3.2), dpi=120, facecolor="white") ax.set_facecolor("white") nodes = {"Ann": (0, 1.8), "Out": (-1.4, 0.8), "Bob": (1.1, 0.8), "Fight": (0.2, -0.35), "Acquiesce": (2, -0.35)} for start, end, label, dx in [("Ann", "Out", "stay out", -0.16), ("Ann", "Bob", "enter", 0.14), ("Bob", "Fight", "fight", -0.13), ("Bob", "Acquiesce", "acquiesce", 0.24)]: x0, y0 = nodes[start] x1, y1 = nodes[end] ax.plot([x0, x1], [y0, y1], color="#526476", linewidth=1.7) ax.text((x0+x1)/2+dx, (y0+y1)/2, label, ha="center", va="center", fontsize=11, bbox={"facecolor": "white", "edgecolor": "none", "pad": 2}) for name in ["Ann", "Bob"]: x, y = nodes[name] ax.scatter([x], [y], s=1300, color="#e6f1fa", edgecolor="#1c5580", zorder=3) ax.text(x, y, name, ha="center", va="center", fontsize=12, zorder=4) for name, payoff in [("Out", "(2, 6)"), ("Fight", "(1, 1)"), ("Acquiesce", "(3, 3)")]: x, y = nodes[name] ax.scatter([x], [y], s=35, color="#1c5580", zorder=3) ax.text(x, y-0.25, payoff, ha="center", va="top", fontsize=13) ax.set_title("Payoffs: (Ann, Bob), in millions", fontsize=13, pad=12) ax.set_xlim(-2, 2.7) ax.set_ylim(-1.0, 2.2) ax.axis("off") fig.tight_layout(pad=0.8) fig.savefig(Path.cwd()/(Path(__file__).stem+".png"), facecolor="white", transparent=False) plt.close(fig) if __name__ == "__main__": main()