如何使用Python和用户自定义函数进行非线性曲线拟合和查找拟合参数？

import numpy as np
import scipy.optimize as optimize
import matplotlib.pyplot as plt

x_data = np.array([1, 2, 3, 4, 5])
y_data = np.array([3, 5, 7, 9, 11])

def custom_func(x, a, b, c):
    return a * np.exp(-b * x) + c

def fit_func(params):
    return y_data - custom_func(x_data, *params)

initial_guess = [1, 1, 1]

result = optimize.leastsq(fit_func, initial_guess)

best_params = result[0]

x_fit = np.linspace(0, 6, 100)
y_fit = custom_func(x_fit, *best_params)

plt.scatter(x_data, y_data, label='Actual Data')
plt.plot(x_fit, y_fit, label='Best Fit Curve')
plt.legend()
plt.xlabel('x')
plt.ylabel('y')
plt.show()