Fix. Default password should be [] not an empty string
line source
% MODIFYTIMESTEP modifies the timestep of a ssm object
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% DESCRIPTION: MODIFYTIMESTEP modifies the timestep of a ssm object, and updates
% the A and B matrices supposing there is no aliasing.
%
% CALL: sys = modifyTimeStep(sys,pl)
%
% INPUTS:
% sys - (array of) ssm objects
% pl - A plist or numeric value giving new timestep value (param name 'newtimestep')
%
% OUTPUTS:
% sys - (array of) ssm
%
% <a href="matlab:utils.helper.displayMethodInfo('ssm', 'modifyTimeStep')">Parameters Description</a>
%
% VERSION: $Id: modifyTimeStep.m,v 1.11 2011/04/08 08:56:23 hewitson Exp $
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function varargout = modifyTimeStep(varargin)
%% Check if this is a call for parameters
if utils.helper.isinfocall(varargin{:})
varargout{1} = getInfo(varargin{3});
return
end
%% send starting message
import utils.const.*
utils.helper.msg(msg.PROC3, 'running %s/%s', mfilename('class'), mfilename);
%% collecting input
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, invars2, rest] = utils.helper.collect_objects(rest(:), 'plist');
% override with a numeric input value
if ~isempty(rest)
% if the user inputs a single numerical value, we use it
if isnumeric(rest{1}) && numel(rest{1}) == 1
if ~isa(pl, 'plist') % perhaps we dont' have a plist yet
pl = plist();
end
pl.pset('newtimestep', rest{1}); % set newtimestep
else
pl = combine(pl, plist(rest{:}));
end
end
pl = combine(pl, getDefaultPlist());
%%% Internal call: Only one object + don't look for a plist
internal = strcmp(varargin{end}, 'internal');
%% dealing with user custom inputs
Nsys = numel(sys);
%% begin function body
%% building output depending on options
sys = copy(sys,nargout);
newtimestep = find(pl,'newtimestep');
outputAntiAlias = find(pl, 'outputAntiAlias');
if numel(newtimestep)~=1
error('parameter "newtimestep" should be of size 1x1')
end
for i = 1:Nsys
if ~sys(i).isnumerical
error(['error in modifTimeStep because system "',sys(i).name, '" should be numerical to be modified' ]);
end
%% retrieving input data
timestep = sys(i).timestep;
sssizes = sys(i).sssizes;
inputsizes = sys(i).inputsizes;
amat = ssm.blockMatFusion(sys(i).amats, sssizes, sssizes);
bmat = ssm.blockMatFusion(sys(i).bmats, sssizes, inputsizes);
if outputAntiAlias
outputsizes = sys(i).outputsizes;
cmat = ssm.blockMatFusion(sys(i).cmats, outputsizes, sssizes);
dmat = ssm.blockMatFusion(sys(i).dmats, outputsizes, inputsizes);
end
%% take different actions depending on old and new timestep
if timestep == newtimestep
action = 'DoNothing';
elseif newtimestep == 0
action = 'MakeContinuous';
str = 'warning because system is sent back to continuous time';
utils.helper.msg(utils.const.msg.MNAME, str);
elseif timestep == 0
action = 'Discretize';
elseif floor(newtimestep/timestep) == newtimestep/timestep
action = 'TakeMultiple';
elseif newtimestep > timestep
action = 'MakeLonger';
else
action = 'MakeShorter';
str = 'warning because system is sent back to shorter time step';
utils.helper.msg(utils.const.msg.MNAME, str);
end
%% proceed with matrix modifications
amat_input = zeros(size(amat));
if isequal(action,'DoNothing')
%% same timestep : do nothing
amat_2 = amat;
bmat_2 = bmat;
elseif isequal(action,'Discretize')
%% from continuous to discrete
amat_2 = expm(amat * newtimestep);
amat_input = ExpInt(amat, newtimestep);
bmat_2 = real(amat_input * bmat);
if outputAntiAlias
cmat_2 = cmat * 0.5*(eye(size(amat_2)) + amat_2);
dmat_2 = dmat + cmat*0.5*bmat_2;
sys(i).cmats = ssm.blockMatRecut(real(cmat_2), outputsizes, sssizes);
sys(i).dmats = ssm.blockMatRecut(real(dmat_2), outputsizes, inputsizes);
end
elseif isequal(action,'MakeContinuous')
%% for discrete to continuous
[V, E] = eig(amat);
amat_2 = real(V * (diag(log(diag(E)))/timestep) * V^(-1));
amat_input = ExpInt(amat_2, timestep);
amat_input_inv = (amat_input)^(-1);
bmat_2 = real(amat_input_inv * bmat);
if outputAntiAlias
cmat_2 = cmat * (0.5*(eye(size(amat)) + amat))^-1;
dmat_2 = dmat - cmat_2*0.5*bmat;
sys(i).cmats = ssm.blockMatRecut(real(cmat_2), outputsizes, sssizes);
sys(i).dmats = ssm.blockMatRecut(real(dmat_2), outputsizes, inputsizes);
end
elseif isequal(action,'TakeMultiple')
%% discrete to discrete with a multiple
multiple = newtimestep/timestep;
amat_2 = amat^multiple;
for i_step = 1:multiple
amat_input = amat_input + amat^(i_step-1);
end
bmat_2 = real(amat_input * bmat);
if outputAntiAlias
cmat_0 = cmat * (0.5*(eye(size(amat)) + amat))^-1;
cmat_2 = cmat_0 * 0.5*(eye(size(amat_2)) + amat_2);
dmat_2 = dmat + cmat_0*0.5*bmat_2 - cmat_0*0.5*bmat;
sys(i).cmats = ssm.blockMatRecut(real(cmat_2), outputsizes, sssizes);
sys(i).dmats = ssm.blockMatRecut(real(dmat_2), outputsizes, inputsizes);
end
elseif isequal(action,'MakeLonger')||isequal(action,'MakeShorter')
%% discrete to discrete with no multiple relationship
[V, E] = eig(amat);
amat_c = real(V * (diag(log(diag(E)))/timestep) * V^(-1));
amat_2 = expm( amat * newtimestep/timestep);
amat_input_1 = ExpInt(amat_c, timestep);
amat_input_2 = ExpInt(amat_c, newtimestep);
bmat_2 = real(amat_input_2 * (amat_input_1)^(-1) * bmat);
if outputAntiAlias
cmat_0 = cmat * (0.5*(eye(size(amat)) + amat))^-1;
cmat_2 = cmat_0 * 0.5*(eye(size(amat_2)) + amat_2);
dmat_2 = dmat + cmat_0*0.5*bmat_2 - cmat_0*0.5*bmat;
sys(i).cmats = ssm.blockMatRecut(real(cmat_2), outputsizes, sssizes);
sys(i).dmats = ssm.blockMatRecut(real(dmat_2), outputsizes, inputsizes);
end
end
amat_2 = real(amat_2);
bmat_2 = real(bmat_2);
%% Save Matrix modifications
sys(i).amats = ssm.blockMatRecut(amat_2, sssizes, sssizes);
sys(i).bmats = ssm.blockMatRecut(bmat_2, sssizes, inputsizes);
sys(i).timestep = newtimestep;
if ~internal
sys(i).addHistory(getInfo('None'), pl, ssm_invars(i), sys(i).hist );
end
end
if nargout == numel(sys)
for ii = 1:numel(sys)
varargout{ii} = sys(ii);
end
else
varargout{1} = sys;
end
end
function A_int = ExpInt(A, t)
niter = 35;
A1 = A*t;
A2 = eye(size(A))*t;
A_int = zeros(size(A));
for i=1:niter
A_int = A_int + A2;
A2 = A1*A2/(i+1);
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.op, '$Id: modifyTimeStep.m,v 1.11 2011/04/08 08:56:23 hewitson Exp $', sets, pl);
end
%--------------------------------------------------------------------------
% Get Default Plist
%--------------------------------------------------------------------------
function pl = getDefaultPlist()
pl = plist();
p = param({'newtimestep', 'Specify the desired new timestep.'}, paramValue.EMPTY_DOUBLE);
pl.append(p);
p = param({'outputAntiAlias', 'Uses a linear averaging method to compute the systems output.'}, paramValue.TRUE_FALSE);
pl.append(p);
end