python高通滤波器设计_Python科学计算——高低通滤波器的设计与使用

总结：先划分窗口，再对每个窗口做高通滤波。不用先滤波再划分。

以下转载自 http://blog.csdn.net/thoughts_storms/article/details/32318921

用Python实现 对一段简单的正弦叠加信号进行高、低通滤波

# -*- coding: utf-8 -*-

from scipy import signal

import numpy as np

import matplotlib.pyplot as pl

import matplotlib

import math

N = 500

fs = 5

n = [2*math.pi*fs*t/N for t in range(N)]

axis_x = np.linspace(0,1,num=N)

#设置字体文件，否则不能显示中文

myfOnt= matplotlib.font_manager.FontProperties(fname=&＃39;c:\\windows\\fonts\\fzshjw_0.ttf&＃39;)

#频率为5Hz的正弦信号

x = [math.sin(i) for i in n]

pl.subplot(221)

pl.plot(axis_x,x)

pl.title(u&＃39;5Hz的正弦信号&＃39;, fOntproperties=myfont)

pl.axis(&＃39;tight&＃39;)

xx = []

x1 = [math.sin(i*10) for i in n]

for i in range(len(x)):

xx.append(x[i] + x1[i])

pl.subplot(222)

pl.plot(axis_x,xx)

pl.title(u&＃39;5Hz与50Hz的正弦叠加信号&＃39;, fOntproperties=myfont)

pl.axis(&＃39;tight&＃39;)

b,a = signal.butter(3,0.08,&＃39;low&＃39;)

sf = signal.filtfilt(b,a,xx)

pl.subplot(223)

pl.plot(axis_x,sf)

pl.title(u&＃39;低通滤波后&＃39;, fOntproperties=myfont)

pl.axis(&＃39;tight&＃39;)

b,a = signal.butter(3,0.10,&＃39;high&＃39;)

sf = signal.filtfilt(b,a,xx)

pl.subplot(224)

pl.plot(axis_x,sf)

pl.title(u&＃39;高通滤波后&＃39;, fOntproperties=myfont)

pl.axis(&＃39;tight&＃39;)