--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/m-toolbox/classes/@ao/minus.m	Wed Nov 23 19:22:13 2011 +0100
@@ -0,0 +1,78 @@
+% MINUS implements subtraction operator for analysis objects.
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% DESCRIPTION: MINUS implements subtraction operator for two analysis objects.
+%
+% CALL:
+%              a = a1-a2
+%              a = minus(a1,a2);
+%              a = minus(a1,a2,a3) == minus(minus(a1,a2),a3)
+%
+% More than two inputs are handled with nested calls.
+%
+% <a href="matlab:utils.helper.displayMethodInfo('ao', 'minus')">Parameters Description</a>
+%
+% VERSION:     $Id: minus.m,v 1.39 2011/04/08 08:56:17 hewitson Exp $
+%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+function varargout = minus(varargin)
+
+  % Settings
+  op       = 'minus';
+  opname   = 'subtract';
+  opsym    = '-';
+  
+  if nargout == 0
+    error('### A %s operator can not be used as a modifier.', opname);
+  end
+  
+  callerIsMethod = utils.helper.callerIsMethod;  
+    
+  if callerIsMethod
+    aosNames = {};
+  else    
+    % collect input variable names
+    for ii = 1:nargin,aosNames{ii} = inputname(ii);end    
+  end
+  
+  % apply operator
+  res = ao.elementOp(callerIsMethod, @getInfo, @getDefaultPlist, op, opname, opsym, aosNames, varargin(:));
+  
+  % Set output
+  varargout = utils.helper.setoutputs(nargout, res);    
+  
+  
+end
+
+%--------------------------------------------------------------------------
+% Get Info Object
+%--------------------------------------------------------------------------
+function ii = getInfo(varargin)
+  
+  if nargin == 1 && strcmpi(varargin{1}, 'None')
+    sets = {};
+    pls  = [];
+  else
+    sets = {'Default'};
+    pls  = getDefaultPlist;
+  end
+  % Build info object
+  ii = minfo(mfilename, 'ao', 'ltpda', utils.const.categories.aop, '$Id: minus.m,v 1.39 2011/04/08 08:56:17 hewitson Exp $', sets, pls);
+  ii.setArgsmin(2);
+end
+
+%--------------------------------------------------------------------------
+% Get Default Plist
+%--------------------------------------------------------------------------
+function plout = getDefaultPlist()
+  persistent pl;  
+  if ~exist('pl', 'var') || isempty(pl)
+    pl = buildplist();
+  end
+  plout = pl;  
+end
+
+function pl = buildplist()
+  pl = plist.EMPTY_PLIST;
+end