Elliptic

An elliptic or Cauer filter can be generated with

cauer ( <order> , <ripple> , <stopband> ) ;

<order>	:	integer; order,
<ripple>	:	real; passband ripple in dB,
<stopband>	:	real; normalized lowest stopband frequency.

The bandwidth of this filter, defined in the same way as for Chebyshev filters, is 1rad/s. The stopband begins at <stopband>, so this variable must be larger than 1.