cheb2mag

Scilab Function
Last update : April 1993

cheb2mag - response of type 2 Chebyshev filter

### Calling Sequence

  `[h2]=cheb2mag(n,omegar,A,sample)`

### Parameters

- `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

### Description

Square magnitude response of a type 2 Chebyshev filter.

`omegar` = stopband edge, `sample` = vector of frequencies where the square magnitude `h2` is desired.

### Examples

    //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")

### See Also

`cheb1mag`,