从matplotlib中导入pyplot和numpy
import matplotlib.pyplot as plt
import numpy as np

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

delta = 2.0
x = np.linspace(-10, 10, 100)
y = np.sinc(x-delta)

plt.axvline(delta, ls="--", color="r")
plt.annotate(r"\delta", xy=(delta+0.2, -0.2), color="r", size=15)
plt.plot(x, y)

plt.show()