利用python和jupyter notebook交互式小部件生成方波，可以实时调节谐波个数和基波频率

import ipywidgets as widgets
from IPython.display import display
import matplotlib.pyplot as plt
import numpy as np

%matplotlib nbagg

fig, ax = plt.subplots(1, figsize=(10, 4))
plt.suptitle(‘square‘)

def plot_exp(f_max, num):
    ax.clear()
    T = 1/f_max
    t=np.linspace(-2, 2, 2000) #0到6T区间内2000个样本
    x = np.zeros_like(t)
    f = f_max
    k=np.arange(1,num) 
    k = 2 * k -1 
    for i in range(2000):
        x[i]= np.sum(np.sin(k*np.pi*f*t[i])/k)
    y = np.real(x)
    ax.plot(t, y)
    plt.show()

f_max = widgets.FloatSlider(min=0, max=1, value=1, description=‘f:‘) #f_max是正弦波基波频率
num = widgets.IntSlider(min=1, max=100, value=1, description=‘num:‘)#num是要叠加的谐波次数
    
widgets.interactive(plot_exp, f_max=f_max,num=num)#设置滑块插件