xinit('analog.4.ps')
n=13;epsilon=0.2;omegac=3;sample=0:0.05:10;
[p,gain]=zpch1(n,epsilon,omegac);
//Transfer function computation tr_fct(s)=gain/deno(s)
tr_fct=poly(gain,'s','coef')/real(poly(p,'s'))
//Magnitude of the frequency response computed along the
//imaginary axis for the values %i*sample...
rep=abs(freq(tr_fct(2),tr_fct(3),%i*sample));   
plot(sample,rep,'frequencies','magnitude')
xend()
         