【matlab】freqz函数的使用(一)

最新推荐文章于 2025-07-15 11:45:54 发布

Treysure

最新推荐文章于 2025-07-15 11:45:54 发布

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本文介绍了MATLAB中的freqz函数，该函数用于计算滤波器的频率响应。通过freqz，可以得到滤波器响应h以及对应的频率w，帮助理解和分析滤波器的性能。

>> help freqz

freqz - Frequency response of filter

滤波器的频率响应

This MATLAB function returns the frequency response h and the corresponding

frequencies w at which the filter response of hfilt is computed.

当计算滤波器响应hfilt时这个MATLAB函数返回频率响应h 和相应频率w

[h,w] = freqz(hfilt)
[h,w] = freqz(hfilt,n)
freqz(hfilt)
[h,w] = freqz(hs)
[h,w] = freqz(hs,n)
[h,w] = freqz(hs,Name,Value)
freqz(hs)

>> wn3 = hamming(10)% 2^(10-1)

wn3 =

    0.0800
    0.1876
    0.4601
    0.7700
    0.9723
    0.9723
    0.7700
    0.4601
    0.1876
    0.0800

>> [h1,w3] = freqz(wn3,1)  % 2^(10-1)

h1 =

   4.9400 + 0.0000i
   4.9378 - 0.1364i
   4.9312 - 0.2726i
   4.9201 - 0.4085i
   4.9047 - 0.5439i
   4.8848 - 0.6787i
   4.8607 - 0.8127i
   4.8322 - 0.9458i
   4.7994 - 1.0777i
   4.7624 - 1.2085i
   4.7212 - 1.3378i
   4.6759 - 1.4655i
   4.6265 - 1.5916i
   4.5732 - 1.7159i
   4.5159 - 1.8382i
   4.4548 - 1.9583i
   4.3899 - 2.0763i
   4.3213 - 2.1918i
   4.2492 - 2.3049i
   4.1736 - 2.4153i
   4.0946 - 2.5230i
   4.0123 - 2.6279i
   3.9269 - 2.7297i
   3.8384 - 2.8286i
   3.7470 - 2.9242i
   3.6528 - 3.0166i
   3.5560 - 3.1057i
   3.4565 - 3.1913i
   3.3547 - 3.2733i
   3.2506 - 3.3518i
   3.1443 - 3.4267i
   3.0360 - 3.4978i
   2.9258 - 3.5651i
   2.8139 - 3.6286i
   2.7005 - 3.6882i
   2.5855 - 3.7439i
   2.4693 - 3.7956i
   2.3520 - 3.8434i
   2.2336 - 3.8871i
   2.1144 - 3.9268i
   1.9945 - 3.9624i
   1.8741 - 3.9940i
   1.7532 - 4.0216i
   1.6321 - 4.0451i
   1.5108 - 4.0646i
   1.3896 - 4.0800i
   1.2686 - 4.0915i
   1.1479 - 4.0990i
   1.0276 - 4.1025i
   0.9080 - 4.1022i
   0.7890 - 4.0979i
   0.6710 - 4.0899i
   0.5539 - 4.0781i
   0.4379 - 4.0627i
   0.3232 - 4.0435i
   0.2099 - 4.0209i
   0.0981 - 3.9947i
  -0.0122 - 3.9651i
  -0.1207 - 3.9321i
  -0.2274 - 3.8959i
  -0.3321 - 3.8565i
  -0.4348 - 3.8140i
  -0.5354 - 3.7685i
  -0.6338 - 3.7202i
  -0.7298 - 3.6690i
  -0.8235 - 3.6151i
  -0.9146 - 3.5587i
  -1.0033 - 3.4998i
  -1.0893 - 3.4385i
  -1.1726 - 3.3749i
  -1.2532 - 3.3092i
  -1.3310 - 3.2415i
  -1.4060 - 3.1718i
  -1.4780 - 3.1003i
  -1.5471 - 3.0272i
  -1.6133 - 2.9525i
  -1.6764 - 2.8764i
  -1.7365 - 2.7989i
  -1.7936 - 2.7203i
  -1.8476 - 2.6405i
  -1.8985 - 2.5598i
  -1.9463 - 2.4782i
  -1.9910 - 2.3959i
  -2.0327 - 2.3130i
  -2.0712 - 2.2296i
  -2.1067 - 2.