% N-ellip 0.2.1 %error: [Zz, Zp, Zg] = ellip(n, Rp, Rs, Wp, stype,'s') % % Generate an Elliptic or Cauer filter (discrete and contnuious). % % [b,a] = ellip(n, Rp, Rs, Wp) % low pass filter with order n, cutoff pi*Wp radians, Rp decibels % of ripple in the passband and a stopband Rs decibels down. % % [b,a] = ellip(n, Rp, Rs, Wp, 'high') % high pass filter with cutoff pi*Wp... % % [b,a] = ellip(n, Rp, Rs, [Wl, Wh]) % band pass filter with band pass edges pi*Wl and pi*Wh ... % % [b,a] = ellip(n, Rp, Rs, [Wl, Wh], 'stop') % band reject filter with edges pi*Wl and pi*Wh, ... % % [z,p,g] = ellip(...) % return filter as zero-pole-gain. % % [...] = ellip(...,'s') % return a Laplace space filter, W can be larger than 1. % % [a,b,c,d] = ellip(...) % return state-space matrices % % References: % % - Oppenheim, Alan V., Discrete Time Signal Processing, Hardcover, 1999. % - Parente Ribeiro, E., Notas de aula da disciplina TE498 - Processamento % Digital de Sinais, UFPR, 2001/2002. % - Kienzle, Paul, functions from Octave-Forge, 1999 (http://octave.sf.net). % % Author: Paulo Neis <p_neis@yahoo.com.br> % Modified: Doug Stewart Feb. 2003