Mercurial > hg > ltpda
view m-toolbox/classes/+utils/@math/pfallpsymz2.m @ 39:11e3ed9d2115 database-connection-manager
Implement databases listing in database connection dialog
author | Daniele Nicolodi <nicolodi@science.unitn.it> |
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date | Mon, 05 Dec 2011 16:20:06 +0100 |
parents | f0afece42f48 |
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% PFALLPSYMZ2 all pass filtering to stabilize TF poles and zeros. % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % DESCRIPTION: % % All pass filtering in order to stabilize transfer function poles and % zeros. It inputs a partial fraction expanded discrete model and % outputs a pole-zero minimum phase system % % CALL: % % resp= pfallpz2(ip,mresp,f,fs) % % INPUTS: % % ip: is a struct with fields named poles % mresp: is a vector with functions response % f: is the frequancies vector in (Hz) % fs: is the sampling frequency in (Hz) % % OUTPUTS: % % resp: is the stable functions frequency response % % NOTE: % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % VERSION: $Id: pfallpz.m,v 1.6 2009/06/10 15:47:00 luigi Exp $ % % HISTORY: 12-09-2008 L Ferraioli % Creation %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% function varargout = pfallpsymz2(ip,mresp,f,fs) [a,b] = size(ip); if a<b ip = ip.'; % reshape as a column vector end [a,b] = size(f); if a<b f = f.'; % reshape as a column vector end if isempty(fs) fs = 1; end [a,b] = size(fs); if a ~= b disp(' Fs has to be a number. Only first term will be considered! ') fs = fs(1); end %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Nb = numel(ip); for nn = 1:Nb p = ip(nn).poles; % stabilizing poles sp = sym(p); unst = abs(p) > 1; sp(unst) = conj(sp(unst)); pp = sym(p(unst)); psp = sp(unst); syms z allpsym = 1; for jj=1:numel(psp) allpsym = allpsym.*((z-pp(jj))./(z*psp(jj)-1)); end funcell{nn} = allpsym; end fullallprsp = 1; for nn = 1:Nb symexpr = funcell{nn}; nterm = subs(symexpr,z,cos((2*pi/fs).*f) + 1i.*sin((2*pi/fs).*f)); % willing to work with columns if size(nterm,2)>1 nterm = nterm.'; end fullallprsp = fullallprsp.*nterm; end % dballprsp = double(fullallprsp); % rallp = real(dballprsp); % iallp = imag(dballprsp); % ang = angle(dballprsp); for kk=1:Nb sresp(:,kk) = mresp(:,kk).*fullallprsp; % resp(:,kk) = mresp(:,kk).*(cos(ang)+1i.*sin(ang)); end for kk=1:Nb resp(:,kk) = double(sresp(:,kk)); end % output if nargout == 1 varargout{1} = resp; else error('Too many output arguments!') end end