--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/m-toolbox/classes/@ssm/ssm2rational.m	Wed Nov 23 19:22:13 2011 +0100
@@ -0,0 +1,134 @@
+% SSM2RATIONAL converts a statespace model object to a rational frac. object
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% DESCRIPTION: SSM2RATIONAL converts a statespace model object to
+%              a rational fraction object.
+%
+% CALL:
+%              >> rats = ssm2rational(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:
+%
+%           rats - an array of rational fraction object
+%
+% <a href="matlab:utils.helper.displayMethodInfo('ssm', 'ssm2rational')">Parameters Description</a>
+%
+% VERSION: $Id: ssm2rational.m,v 1.19 2011/04/08 08:56:23 hewitson Exp $
+% 
+% IMPLEMENTATION NOT FINISHED!!!!
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+function varargout = ssm2rational(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] = double(sys, pl);
+  
+  Ninputs_out  = numel(inputvarnames);
+  Noutputs_out = numel(outputvarnames);
+  
+  if Ts > 0
+    error('system should be time continuous. Use ssm2miir instead');
+  else
+    %% convert to pzm
+    rational_out(Noutputs_out, Ninputs_out) = rational();
+    for ii=1:Ninputs_out
+      for oo=1:Noutputs_out
+        sys_loc =ss( A,B(:,ii),C(oo,:),D(oo, ii ),Ts);
+        sys_loc = minreal(sys_loc);
+        [A_loc, B_loc, C_loc, D_loc]=ssdata(sys_loc);
+        [b,a] = ss2tf(A_loc, B_loc, C_loc, D_loc);
+        name = [ssm_invars{1},' : ',inputvarnames{ii},' -> ',outputvarnames{oo}];
+        if isequal(b,0) || isequal(a,0)
+          m = rational();
+        else
+          m = rational(real(b), real(a), 1/sys.timestep);
+        end
+        m.addHistory(ssm.getInfo(mfilename), pl , ssm_invars, sys.hist);
+        m.name = name;
+        rational_out(oo, ii) = m;
+      end
+    end
+  end
+  if nargout == numel(rational_out)
+    for ii = 1:numel(rational_out)
+      varargout{ii} = rational_out(ii);
+    end
+  else
+    varargout{1} = rational_out;
+  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.converter, '$Id: ssm2rational.m,v 1.19 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
+