line source
+ − % SSM2PZMODEL converts a time-continuous statespace model object to a pzmodel
+ − %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+ − %
+ − % DESCRIPTION: SSM2PZMODEL converts a time-continuous statespace model
+ − % object to a pzmodel
+ − %
+ − % CALL:
+ − % >> pzms = ssm2pzmodel(ssm, pl);
+ − %
+ − % INPUT :
+ − %
+ − % ssm - a ssm object
+ − % pl - a plist with parameters 'inputs', 'states' and
+ − % 'outputs' to indicate which inputs, states and output
+ − % variables are taken in account. This requires proper
+ − % variable naming. If a variable called appears more
+ − % that once it will be used once only.
+ − %
+ − % OUTPUT:
+ − %
+ − % pzms - an array of pzmodels objects if the timestep is zero
+ − %
+ − % <a href="matlab:utils.helper.displayMethodInfo('ssm', 'ssm2pzmodel')">Parameters Description</a>
+ − %
+ − % VERSION: $Id: ssm2pzmodel.m,v 1.21 2011/04/08 08:56:23 hewitson Exp $
+ − %
+ − %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+ −
+ − function varargout = ssm2pzmodel(varargin)
+ −
+ − % Check if this is a call for parameters
+ − if utils.helper.isinfocall(varargin{:})
+ − varargout{1} = getInfo(varargin{3});
+ − return
+ − end
+ −
+ − %% starting initial checks
+ − utils.helper.msg(utils.const.msg.MNAME, ['running ', mfilename]);
+ −
+ − % Collect input variable names
+ − in_names = cell(size(varargin));
+ − for ii = 1:nargin,in_names{ii} = inputname(ii);end
+ −
+ − % Collect all SSMs and plists
+ − [sys, ssm_invars, rest] = utils.helper.collect_objects(varargin(:), 'ssm', in_names);
+ − [pl, invars2, rest] = utils.helper.collect_objects(rest(:), 'plist');
+ − if ~isempty(rest)
+ − pl = combine(pl, plist(rest{:}));
+ − end
+ − pl = combine(pl, getDefaultPlist);
+ −
+ − if numel(sys) ~= 1
+ − error('### Input (only) one SSM object.');
+ − end
+ −
+ − %% begin function body
+ −
+ − %% convert to double
+ − % Convert to double arrays
+ − [A,B,C,D,Ts,inputvarnames,ssvarnames,outputvarnames, inputunit, ssunit, outputunit] =...
+ − double(sys, pl);
+ −
+ − Ninputs_out = numel(inputvarnames);
+ − Noutputs_out = numel(outputvarnames);
+ −
+ − if Ts > 0
+ − error('ssm should be time continuous, use ssm2miir instead')
+ − end
+ − %% convert to pzm
+ − pzm_out = pzmodel.initObjectWithSize(Noutputs_out, Ninputs_out);
+ − for ii=1:Ninputs_out
+ − for oo=1:Noutputs_out
+ − [b,a] = ss2tf(A,B(:,ii),C(oo,:),D(oo, ii));
+ − % computing poles and zeros
+ − pa = roots(a);
+ − if isempty(pa)
+ − p = pz.initObjectWithSize(1,0);
+ − gainP = 1;
+ − else
+ − [p, gainP] = roots2poly(pa);
+ − end
+ − zb = roots(b);
+ − if isempty(zb)
+ − z = pz.initObjectWithSize(1,0);
+ − gainZ = 1;
+ − else
+ − [z, gainZ] = roots2poly(zb);
+ − end
+ − % computing gain coefficient
+ − apos = a(a~=0);
+ − bpos = b(b~=0);
+ − if ~isempty(bpos) && ~isempty(apos)
+ − Gain = bpos(1)/apos(1);
+ − elseif ~isempty(apos)
+ − Gain = 1/apos(1);
+ − elseif ~isempty(bpos) % NB theoretically impossible to reach : SSM can't have more zeros than poles
+ − Gain = bpos(1);
+ − else
+ − Gain = 0;
+ − end
+ − Gain = Gain / gainP * gainZ;
+ − % constructing output pzm
+ − name = [sys.name,'_',num2str(ii),':',num2str(oo)];
+ − pzm_out(oo,ii) = pzmodel(plist(...
+ − 'gain', Gain, 'poles', p, 'zeros', z, 'name', name, ...
+ − 'inunits', inputunit(ii), 'ounits' ,outputunit(oo) ));
+ − pzm_out(oo,ii).addHistory(ssm.getInfo(mfilename), pl , ssm_invars, sys.hist);
+ − end
+ − end
+ − if nargout == numel(pzm_out)
+ − for ii = 1:numel(pzm_out)
+ − varargout{ii} = pzm_out(ii);
+ − end
+ − else
+ − varargout{1} = pzm_out;
+ − end
+ − end
+ −
+ −
+ − function varargout = roots2poly(roots)
+ − poly = pz.initObjectWithSize(1,0);
+ − i=1;
+ − gain = 1;
+ − while i < length(roots)+1
+ − if isreal(roots(i))
+ − poly = [poly pz(-roots(i)/2/pi)]; %#ok<AGROW>
+ − gain = gain * abs(roots(i));
+ − i = i+1;
+ − else
+ − f = norm(roots(i)/2/pi);%*sign(real(roots(i)));
+ − Q = norm(roots(i))/abs(2*real(roots(i)));
+ − poly = [poly pz(f,Q)]; %#ok<AGROW>
+ − gain = gain * abs(roots(i))^2;
+ − i = i+2; %#ok<FXSET>
+ − end
+ − end
+ − varargout = {poly, gain};
+ − end
+ −
+ −
+ − %--------------------------------------------------------------------------
+ − % Get Info Object
+ − %--------------------------------------------------------------------------
+ − function ii = getInfo(varargin)
+ −
+ − if nargin == 1 && strcmpi(varargin{1}, 'None')
+ − sets = {};
+ − pl = [];
+ − else
+ − sets = {'Default'};
+ − pl = getDefaultPlist;
+ − end
+ − % Build info object
+ − ii = minfo(mfilename, 'ssm', 'ltpda', utils.const.categories.converter, '$Id: ssm2pzmodel.m,v 1.21 2011/04/08 08:56:23 hewitson Exp $', sets, pl);
+ − end
+ −
+ − %--------------------------------------------------------------------------
+ − % Get Default Plist
+ − %--------------------------------------------------------------------------
+ − function pl = getDefaultPlist()
+ − pl = plist();
+ −
+ − p = param({'inputs', ['Specify the inputs. Give one of:<ul>'...
+ − '<li>A cell-array of input port names.</li>'...
+ − '<li>A cell-array of logical arrays specifying which input ports to use for each input block.</li>'...
+ − '<li>A cell-array of double values specifying which input ports to use for each input block.<li>'...
+ − '<li>The string ''ALL'' to use all inputs.']}, paramValue.STRING_VALUE('ALL'));
+ − pl.append(p);
+ −
+ − p = param({'states', 'Specify the states. Specify the states as for the ''inputs'' parameter.'}, paramValue.STRING_VALUE('ALL'));
+ − pl.append(p);
+ −
+ − p = param({'outputs', 'Specify the outputs. Specify the outputs as for the ''inputs'' parameter.'}, paramValue.STRING_VALUE('ALL'));
+ − pl.append(p);
+ − end
+ −