python滤波器对原始数据连续处理和分段处理

# -*- coding: utf-8 -*-import scipy.signal as signalimport numpy as npimport matplotlib.pyplot as plt# 某个均衡滤波器的参数a = np.array([1.0, -1.947463016918843, 0.9555873701383931])b = np.array([0.9833716591860479, -1.947463016918843, 0.9722157109523452])# 44.1kHz， 1秒的频率扫描波t = np.arange(0, 0.5, 1 / 44100.0)x = signal.chirp(t, f0=10, t1=0.5, f1=1000.0)#直接一次计算出所有的yy = signal.lfilter(b,a,x)## #绘图# plt.figure(1)# plt.subplot(211)# plt.plot(t,x,'r')# plt.subplot(212)# plt.plot(t,y,'k')# plt.show()#分批依次计算yx2=x.reshape(-1,50)#滤波器的初始状态为0，长度是滤波器系数长度-1z = np.zeros(max(len(a),len(b))-1,dtype=np.float)y2=[]for tx in x2:    #对于每段信号进行滤波，新的初始状态保存在z中    ty,z=signal.lfilter(b,a,tx,zi=z)    y2.append(ty)y2=np.array(y2)y2=y2.reshape((-1,))print np.sum((y-y2)**2)#将三个信号绘图plt.figure(1)plt.subplot(311)plt.plot(t,x,'r')plt.title('original data')plt.subplot(312)plt.plot(y,x,'b')plt.title('calculate onec time')plt.subplot(313)plt.plot(y2,x,'k')plt.title('calculate uncontinuously')plt.show()