RZ2IIR Return a,b IIR filter coefficients for a real zero designed using the bilinear transform. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% DESCRIPTION: RZ2IIR Return a,b IIR filter coefficients for a real zero designed using the bilinear transform. CALL: [a,b] = rz2iir(z, fs) INPUT: z - zero object fs - the sample rate for the filter VERSION: $Id: rz2iir.m,v 1.3 2007/07/18 13:58:45 ingo Exp $ HISTORY: 18-02-2003 Hewitson Creation %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
0001 function [a,b] = rz2iir(z, fs) 0002 % RZ2IIR Return a,b IIR filter coefficients for a real zero designed using the bilinear transform. 0003 % 0004 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 0005 % 0006 % DESCRIPTION: RZ2IIR Return a,b IIR filter coefficients for a real zero 0007 % designed using the bilinear transform. 0008 % 0009 % CALL: [a,b] = rz2iir(z, fs) 0010 % 0011 % INPUT: z - zero object 0012 % fs - the sample rate for the filter 0013 % 0014 % VERSION: $Id: rz2iir.m,v 1.3 2007/07/18 13:58:45 ingo Exp $ 0015 % 0016 % HISTORY: 18-02-2003 Hewitson 0017 % Creation 0018 % 0019 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 0020 0021 f0 = get(z, 'f'); 0022 0023 w0 = f0*2*pi; 0024 0025 a(1) = (2*fs + w0) / w0; 0026 a(2) = (-2*fs + w0) / w0; 0027 0028 b(1) = 1; 0029 b(2) = 1;