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// Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
// Copyright (C) INRIA - F.D
//
// This file must be used under the terms of the CeCILL.
// This source file is licensed as described in the file COPYING, which
// you should have received as part of this distribution. The terms
// are also available at
// http://www.cecill.info/licences/Licence_CeCILL_V2.1-en.txt
function [h2]=cheb1mag(n,omegac,epsilon,sampleFreq)
//<h2>=cheb1mag(n,omegac,epsilon,sample)
//Square magnitude response of a type 1 Chebyshev filter
//omegac=passband edge
//epsilon such that 1/(1+epsilon**2)=passband ripple
//sample vector of frequencies where the square magnitude
//is desired.
// n :Filter order
// omegac :Cut-off frequency
// epsilon :Ripple in pass band
// sample :Vector of frequency where cheb1mag is evaluated
// h2 :Chebyshev I filter values at sample points
//
//!
[n1,n2]=size(sampleFreq);
un=ones(n1,n2);
Tn=chepol(n,"x"); //n-th Chebyshev polynomial
fr=freq(Tn,1,sampleFreq/omegac); //fr=Tn(sample/omegac)
h2=un./(un+epsilon*epsilon*fr.*fr) //magnitude
endfunction
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