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  • Committer: Bazaar Package Importer
  • Author(s): Torsten Werner
  • Date: 2002-03-21 16:57:43 UTC
  • Revision ID: james.westby@ubuntu.com-20020321165743-e9mv12c1tb1plztg
Tags: upstream-2.6
Import upstream version 2.6

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macros/signal/cheb1mag.sci
 
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function [h2]=cheb1mag(n,omegac,epsilon,sample)
 
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//<h2>=cheb1mag(n,omegac,epsilon,sample)
 
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//Square magnitude response of a type 1 Chebyshev filter
 
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//omegac=passband edge
 
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//epsilon such that 1/(1+epsilon**2)=passband ripple
 
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//sample vector of frequencies where the square magnitude
 
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//is desired.
 
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//  n       :Filter order
 
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//  omegac  :Cut-off frequency
 
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//  epsilon :Ripple in pass band
 
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//  sample  :Vector of frequency where cheb1mag is evaluated
 
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//  h2      :Chebyshev I filter values at sample points
 
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//
 
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//!
 
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//Author F.D.
 
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// Copyright INRIA
 
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   [n1,n2]=size(sample);
 
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   un=ones(n1,n2);
 
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   Tn=chepol(n,'x');  //n-th Chebyshev polynomial
 
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   fr=freq(Tn,1,sample/omegac);   //fr=Tn(sample/omegac)
 
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   h2=un./(un+epsilon*epsilon*fr.*fr)   //magnitude
 
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