--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/m-toolbox/classes/@ssm/ssmFromRational.m	Wed Nov 23 19:22:13 2011 +0100
@@ -0,0 +1,83 @@
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% FUNCTION:    ssmFromRational
+%
+% DESCRIPTION: Construct a statespace model from a rational
+%
+% CALL:        see ssm, this function is private
+%
+% TODO:        check must be made there is no pole zero cancelation
+%
+% VERSION :    '$Id: ssmFromRational.m,v 1.13 2011/03/23 20:05:37 adrien Exp $';
+%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+function varargout = ssmFromRational(varargin)
+  
+  VERSION = '$Id: ssmFromRational.m,v 1.13 2011/03/23 20:05:37 adrien Exp $';
+  utils.helper.msg(utils.const.msg.MNAME, ['running ', mfilename]);
+  % get info
+  ii = ssm.getInfo('ssm', 'From Description');
+  % Set the method version string in the minfo object
+  ii.setMversion([VERSION '-->' ii.mversion]);
+  
+  if nargin ~=2
+    error('ssmFromRational need 2 inputs : (obj, plist) ')
+  elseif isa(varargin{1}, 'rational') && isa(varargin{2}, 'plist')
+    pl = combine(varargin{2}, ii.plists);
+    rationalsin = varargin{1};
+  else
+    error('### Please input  (<object>,<plist>)');
+  end
+  
+  
+  ssmout = ssm.initObjectWithSize(size(rationalsin,1),size(rationalsin,2));
+  for i =1:numel(rationalsin)
+    num =  rationalsin(i).num;
+    den =  rationalsin(i).den;
+    num = num/den(1);
+    den = den/den(1);
+    Nss = size(den,2)-1;
+    if length(num)<Nss+1
+      num = [zeros(1,Nss+1-length(num)) num];
+    end
+    [q,r] = deconv(num,den);%polynmial division for den = conv(num,q)+r .
+    if ~length(q)==1
+      error('system may be non caussal');
+    end
+    
+    ssmout(i).dmats = {q};
+    ssmout(i).amats = {[zeros(Nss-1,1) eye(Nss-1); fliplr(-den(2:(Nss+1)))]};
+    ssmout(i).bmats = {zeros(Nss,1)};
+    if Nss>0
+      ssmout(i).bmats{1}(Nss) = 1;
+    end
+    ssmout(i).cmats = {fliplr(r(2:(Nss+1)))};
+    
+    ssmout(i).name  = rationalsin(i).name;
+    ssmout(i).timestep = 0;
+    
+    inputstr = 'input';
+    outputstr = 'output';
+    ssstr =  'state';
+    
+    ssmout(i).inputs = ssmblock.makeBlocksWithData({inputstr},[],{{inputstr}}, {rationalsin(i).iunits},[]  );
+    ssmout(i).outputs = ssmblock.makeBlocksWithData({outputstr},[],{{outputstr}}, {rationalsin(i).ounits},[] );
+    ssmout(i).states = ssmblock.makeBlocksWithSize(Nss, ssstr);
+    
+    ssmout(i).addHistory(ii, pl, {''}, rationalsin(i).hist);
+    
+        
+    if ~strcmp(pl.find('name'),'None')
+      ssmout(i).name = pl.find('name');
+    end
+    if ~strcmp(pl.find('description'),'')
+      ssmout(i).description = pl.find('description');
+    end
+    
+  end
+  
+  varargout = {ssmout};
+end
+
+