python使用反函数还原输入

import  numpy as np
import matplotlib.pyplot as plt
from pynverse import inversefunc

def my_tah(x):
    sigma =  -0.1
    # base_tah = np.tanh(x)
    # base_tah = (2/(1+np.exp(-2*x))) - 1
    base_tah = (2 / (1 + np.exp(sigma * x))) - 1
    result = 5*base_tah
    return result

if __name__ == '__main__':
    a = np.linspace(-200,200,500)
    tah_a = my_tah(a)                            #   自定义的tanh变种函数
    tah_inverse = inversefunc(my_tah,tah_a)     #   反函数还原
    plt.subplot(121)
    plt.plot(a ,tah_a)
    plt.subplot(122)
    plt.plot(a, tah_inverse)
    # plt.axis('off')
    plt.show()