求助各位大佬

There’s no value for \gamma, maybe following code work for you.

import numpy as np
import matplotlib.pyplot as plt

g   = 0.5
d   = 1.5
n1  = 3
n2  = 10 + 1
x1  = 0
dx  = 0.0001
x2  = 2 + dx
ga  = 2

x = np.arange(x1, x2, dx)[:, None]
n = np.arange(n1, n2)[None, :]
z = g**(d-1)*np.sum(np.cos(2*np.pi*ga**n*x)/(ga**((2-d)*n)), axis=1)

plt.plot(x, z)
plt.show()