gusucode.com > 语音信号处理工具箱 - Voicebox源码程序 > Voicebox\lpczz2ss.m
function ss=lpczz2ss(zz) %LPCZZ2SS Convert z-place poles to s-plane poles SS=(ZZ) %the s-plane is in units of Normalized Hz and so the imaginary part % of each ss() value is in the range +-0.5 % % If you multiply ss by the sample frequency, a formant with % frequency f and bandwidth b will give an s-plane pole-pair % of approximately -b/2 +- j f % Copyright (C) Mike Brookes 1997 % % Last modified Tue May 12 16:15:50 1998 % % VOICEBOX home page: http://www.ee.ic.ac.uk/hp/staff/dmb/voicebox/voicebox.html % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % This program is free software; you can redistribute it and/or modify % it under the terms of the GNU General Public License as published by % the Free Software Foundation; either version 2 of the License, or % (at your option) any later version. % % This program is distributed in the hope that it will be useful, % but WITHOUT ANY WARRANTY; without even the implied warranty of % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the % GNU General Public License for more details. % % You can obtain a copy of the GNU General Public License from % ftp://prep.ai.mit.edu/pub/gnu/COPYING-2.0 or by writing to % Free Software Foundation, Inc.,675 Mass Ave, Cambridge, MA 02139, USA. %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% ss=log(max(zz,1e-8))*0.5/pi;