exnorm

import numpy as np
import matplotlib.pyplot as plt
from scipy.stats import norm

x = np.linspace(-2, 2, 100)

L = [1/2, 1, 2]

s1 = ['*-', '.-', 'o-']

s2 = ['$\sigma=\frac{1}{2a},$', '$\sigma=1,$', '$\sigma=2$']

plt.rc('font', family='SimHei')
plt.rc('axes', unicode_minus=False)

plt.figure(figsize=(8, 5))

for i in range(len(L)):
plt.plot(x, norm.pdf(x, loc=0, scale=L[i]), s1[i], label=s2[i]) # loc=0 是均值

plt.xlabel('$x$')
plt.ylabel('$f(x)$')
plt.title('正态分布的概率密度函数')
plt.legend()
plt.grid()

plt.show()