Scilab Reference Manual |
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cheb2mag — response of type 2 Chebyshev filter
[h2]=cheb2mag(n,omegar,A,sample)
n | : integer ; filter order |
omegar | : real scalar : cut-off frequency |
A | : attenuation in stop band |
sample | : vector of frequencies where cheb2mag is evaluated |
h2 | : vector of Chebyshev II filter values at sample points |
Square magnitude response of a type 2 Chebyshev filter.
omegar = stopband edge, sample = vector of frequencies where the square magnitude h2 is desired.
//Chebyshev; ripple in the stopband n=10;omegar=6;A=1/0.2;sample=0.0001:0.05:10; h2=cheb2mag(n,omegar,A,sample); plot(sample,log(h2)/log(10),'frequencies','magnitude in dB') //Plotting of frequency edges minval=(-maxi(-log(h2)))/log(10); plot2d([omegar;omegar],[minval;0],[2],"000"); //Computation of the attenuation in dB at the stopband edge attenuation=-log(A*A)/log(10); plot2d(sample',attenuation*ones(sample)',[5],"000")
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