from matplotlib import pyplot as plt
import numpy as np

plt.rcParams["figure.figsize"] = [7.50, 3.50]
plt.rcParams["figure.autolayout"] = True

x = np.arange(0, 10, 0.05)
y = np.sin(x)

#定义置信区间
ci = 0.1 * np.std(y) / np.mean(y)

plt.plot(x, y, color='black', lw=7)

plt.fill_between(x, (y-ci), (y+ci), color='blue', alpha=0.5)

plt.show()