--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/m-toolbox/classes/@smodel/sop.m	Wed Nov 23 19:22:13 2011 +0100
@@ -0,0 +1,60 @@
+% SOP apply a symbolic operation to the expression.
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% DESCRIPTION: SOP apply a symbolic operation to the expression.
+% objects.
+%
+% CALL:        obj = sop(mdl, plist)
+%              obj = mdl.sop(plist)
+%
+% <a href="matlab:utils.helper.displayMethodInfo('smodel', 'sop')">Parameters Description</a>
+%
+% VERSION:     $Id: sop.m,v 1.7 2011/04/08 08:56:28 hewitson Exp $
+%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+function sop(mdls, callerIsMethod, smodel_invars, operation, args, pl, info, varargin)
+  
+  import utils.const.*
+  
+  if isempty(operation)
+    error('### Please give a valid symbolic operator');
+  end
+    
+  % Loop over the input objects
+  for jj = 1:numel(mdls)
+    % Message
+    utils.helper.msg(msg.PROC1, 'applying %s to %s ', operation, mdls(jj).name);
+    
+    % Fix syntax (replacing .* with * and so) to allow symbolic evaluation
+    mdls(jj).expr.s = utils.prog.convertComString(mdls(jj).expr.s , 'ToSymbolic');
+    
+    % Go symbolic now
+    d = feval(operation, sym(mdls(jj).expr.s), args{:});
+    
+    % Go back to string
+    mdls(jj).expr.s = utils.prog.mup2mat(d);
+    
+    % Replace * like expressions with .* to allow numeric evaluation
+    mdls(jj).expr.s = utils.prog.convertComString(mdls(jj).expr.s , 'FromSymbolic');
+        
+    % In the case of transforms, sets the new x variable
+    switch lower(operation)
+      case {'laplace', 'ilaplace', 'fourier', 'ifourier', 'ztrans', 'iztrans'}
+        if ~isempty(args)
+          % The return variable is the last argument
+          mdls(jj).xvar = args{end};
+        end
+      otherwise
+    end
+
+    if ~callerIsMethod
+      % Set new AO name
+      mdls(jj).name = [operation '(' smodel_invars{jj} ')'];
+      % Add history step
+      mdls(jj).addHistory(info, pl, smodel_invars(jj), mdls(jj).hist);
+    end
+  end
+  
+end
+