为什么x,y坐标中的标签不会半透明呢,教程中的图片如图
但是实际的图片是这样的
为什么我的没有半透明的背景呢
代码如下:
#!python3
# coidng="utf-8"
import matplotlib.pyplot as plt
import numpy as np
if __name__ == "__main__":
X = np.linspace(-np.pi, np.pi, 256, endpoint=True)
S, Y = np.sin(X), X
plt.figure(figsize=(10, 6), dpi=80)
plt.subplot(111)
plt.xlim(-np.pi * 1.1, np.pi * 1.1)
plt.ylim(min(Y) * 1.1, max(Y) * 1.1)
plt.xticks([-np.pi, -np.pi / 2, 0, np.pi / 2, np.pi],
[r"$-\pi$", r"$-\pi/2$", r"$0$", r"$+\pi/2$", r"$+\pi$"])
plt.yticks([-np.pi, -np.pi / 2, 0, np.pi / 2, np.pi],
[r"$-\pi$", r"$-\pi/2$", r"$0$", r"$+\pi/2$", r"$+\pi$"])
ax = plt.gca()
ax.spines["top"].set_color("none")
ax.spines["right"].set_color("none")
ax.xaxis.set_ticks_position("bottom")
ax.yaxis.set_ticks_position("left")
ax.spines["bottom"].set_position(["data", 0])
ax.spines["left"].set_position(["data", 0])
for each in ax.get_xticklabels() + ax.get_yticklabels():
each.set_fontsize(16)
each.set_bbox(dict(facecolor="white", edgecolor="None", alpha=0.65))
plt.plot(X, S, linewidth=2.5, color="blue", linestyle="-")
plt.plot(X, Y, linewidth=2.5, color="red", linestyle="-")
t = np.pi / 2
plt.plot([t, t], [0, 1], linewidth=1.5, color="blue", linestyle="--")
plt.plot([0, t], [1, 1], linewidth=1.5, color="blue", linestyle="--")
plt.scatter([t, ], [1, ], 50, color="blue")
plt.plot([-t, -t], [0, -t], linewidth=1.5, color="red", linestyle="--")
plt.plot([0, -t], [-t, -t], linewidth=1.5, color="red", linestyle="--")
plt.scatter([-t, ], [-t, ], 50, color="red")
plt.annotate(r"$\sin(\frac{\pi}{2})=1$", xy=(t, 1), xycoords="data", xytext=(+10, +20),
textcoords="offset points", fontsize=16,
arrowprops=dict(arrowstyle="->", connectionstyle="arc3,rad=.2"))
plt.annotate(r"$(\frac{-\pi}{2},\frac{-\pi}{2})$", xy=(-t, -t), xycoords="data", xytext=(+10, -20),
textcoords="offset points", fontsize=16,
arrowprops=dict(arrowstyle="->", connectionstyle="arc3,rad=.2"))
plt.savefig(r'C:\Users\rengz\Desktop\exercice_7.png')
plt.show()
附图