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+ − % RESPCST gives the timewise impulse response of a statespace model.
+ − %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+ − %
+ − % DESCRIPTION: RESPCST gives the timewise impulse response of a statespace
+ − % model.
+ − %
+ − % CALL: [aos ] = respcst(sys, plist_inputs)
+ − %
+ − % INPUTS:
+ − % - sys, (array of) ssm object
+ − %
+ − % plist with parameters 'inputs', 'states' and 'outputs' to indicate which
+ − % inputs, states and outputs variables are taken in account. This requires
+ − % proper variable naming. If a variable called appears more that once it
+ − % will be used once only.
+ − %
+ − % OUTPUTS:
+ − % - aos the timewise response (one for each input)
+ − %
+ − % <a href="matlab:utils.helper.displayMethodInfo('ssm', 'respcst')">Parameters Description</a>
+ − %
+ − % VERSION: $Id: respcst.m,v 1.8 2011/04/08 08:56:23 hewitson Exp $
+ − %
+ − %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+ −
+ − function varargout = respcst(varargin)
+ − %% starting initial checks
+ − % Check if this is a call for parameters
+ − if utils.helper.isinfocall(varargin{:})
+ − varargout{1} = getInfo(varargin{3});
+ − return
+ − end
+ −
+ − utils.helper.msg(utils.const.msg.MNAME, ['running ', mfilename]);
+ −
+ − % checking number of inputs work data
+ − in_names = cell(size(varargin));
+ − for ii = 1:nargin,in_names{ii} = inputname(ii);end
+ −
+ − [sys, ssm_invars, rest] = utils.helper.collect_objects(varargin(:), 'ssm', in_names);
+ − [pl, ssm_invars2, rest] = utils.helper.collect_objects(rest(:), 'plist', in_names);
+ − if ~isempty(rest)
+ − pl = combine(pl, plist(rest{:}));
+ − end
+ − pl = combine(pl, getDefaultPlist());
+ −
+ −
+ − %% begin function body
+ − if numel(sys)>1
+ − error('ssm/respcst only works with a single statespace model.')
+ − end
+ −
+ − if ~sys.isnumerical
+ − error('The input system should be numeric.')
+ − end
+ −
+ − %% modifying input ssm
+ − if sys.timestep == 0
+ − sys = copy(sys, true);
+ − sys.modifyTimeStep(0.1);
+ − warning('Warning : time-continuous ssm was discretized with a time-step of 0.1s per default') %#ok<WNTAG>
+ − end
+ −
+ − %% getting duration of the response
+ − tmax = find(pl, 'tmax');
+ − if sys.isStable && (tmax == -1)
+ − pl_s = settlingTime(sys, pl);
+ − timeMax = min(find(pl_s, 'SETTLING_TIME'), 1e5);
+ − timeMax = 2^nextPow2( 12* timeMax);
+ − else
+ − timeMax = 2^nextPow2( tmax./sys.timestep);
+ − end
+ −
+ − %% deriving and initializing matrices
+ − if find(pl, 'reorganize')
+ − sys = copy(sys, true);
+ − sys = reorganize(sys, pl, 'set', 'for resp', 'internal', 'internal');
+ − end
+ −
+ − A = sys.amats{1,1};
+ − B = sys.bmats{1,1};
+ − C = sys.cmats{2,1};
+ − Cstates = sys.cmats{1,1};
+ − D = sys.dmats{2,1};
+ − Ts = sys.timestep;
+ − Dstates = zeros(size(Cstates,1), size(D,2));
+ − Dtot = [Dstates; D];
+ −
+ − Ninputs = size(B,2);
+ − Noutputs = size(C,1);
+ − Nss = size(A,1);
+ − NssOut = size(Cstates,1);
+ −
+ − %% collecting data before saving in loop
+ − aos = ao.initObjectWithSize(Noutputs+NssOut, Ninputs);
+ − myinfo = getInfo('None');
+ − inhist = sys.hist;
+ −
+ − inputType = find(pl, 'response');
+ −
+ −
+ − for ii=1:Ninputs
+ − sys_ss = ss(A, B(:,ii), [Cstates; C], Dtot(:,ii), Ts);
+ −
+ − %% depending on user option, compute response for one input only
+ − if strcmpi( inputType, 'IMPULSE')
+ − Y = impulse(sys_ss, 1:Ts:(timeMax*Ts));
+ − elseif strcmpi( inputType, 'STEP')
+ − Y = step(sys_ss, 1:Ts:(timeMax*Ts));
+ − else
+ − error(['Option ''response'' does not accept the value' inputType]);
+ − end
+ −
+ − %% storing responsei in aos for one input only
+ −
+ − for oo=1:NssOut;
+ − aos(oo,ii).setData(tsdata( Y(:,oo), 1/Ts));
+ − aos(oo,ii).setName([sys.inputs(1).ports(ii).name '->' sys.outputs(1).ports(oo).name]);
+ − aos(oo,ii).setXunits('s');
+ − aos(oo,ii).setYunits(sys.outputs(1).ports(oo).units);
+ − aos(oo,ii).setDescription([inputType ' response from input ' , sys.inputs(1).ports(ii).name , 'to output ', sys.outputs(1).ports(oo).name]);
+ − aos(oo,ii).setT0(sys.timestep);
+ − aos(oo,ii).addHistory(myinfo, pl , {''}, inhist );
+ − end
+ − for oo=1:Noutputs;
+ − aos(NssOut+oo,ii).setData(tsdata( Y(:,NssOut+oo), 1/Ts));
+ − aos(NssOut+oo,ii).setName([sys.inputs(1).ports(ii).name '->' sys.outputs(2).ports(oo).name]);
+ − aos(NssOut+oo,ii).setXunits('s');
+ − aos(NssOut+oo,ii).setYunits(sys.outputs(2).ports(oo).units);
+ − aos(NssOut+oo,ii).setDescription([inputType ' response from input ' , sys.inputs(1).ports(ii).name , 'to output ', sys.outputs(2).ports(oo).name]);
+ − aos(NssOut+oo,ii).setT0(sys.timestep);
+ − aos(NssOut+oo,ii).addHistory(myinfo, pl , {''}, inhist );
+ − end
+ − end
+ −
+ − %% Set output depending on nargout
+ − if nargout == numel(aos)
+ − for jj=1:nargout
+ − varargout{jj} = aos(jj);
+ − end
+ − elseif nargout == 1;
+ − varargout{1} = aos;
+ − elseif nargout == 0;
+ − iplot(aos);
+ − else
+ − error('Wrong number of outputs')
+ − end
+ − 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.sigproc, '$Id: respcst.m,v 1.8 2011/04/08 08:56:23 hewitson Exp $', sets, pl);
+ − end
+ −
+ − %--------------------------------------------------------------------------
+ − % Get Default Plist
+ − %--------------------------------------------------------------------------
+ −
+ − function pl = getDefaultPlist()
+ − pl = ssm.getInfo('reorganize', 'for resp').plists;
+ − pl.remove('set');
+ −
+ − p = param({'response', 'Specify the type of response wanted'},{1, {'impulse', 'step'}, paramValue.SINGLE} );
+ − pl.append(p);
+ −
+ − p = param({'tmax', 'Specify the duration of response wanted [s] (automatically set if not specified by user, and system is stable)'},-1 );
+ − pl.append(p);
+ −
+ − p = param({'reorganize', 'When set to 0, this means the ssm does not need be modified to match the requested i/o. Faster but dangerous!'}, paramValue.TRUE_FALSE);
+ − pl.append(p);
+ −
+ −
+ − end
+ −