--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/m-toolbox/classes/@ao/filtfilt.m	Wed Nov 23 19:22:13 2011 +0100
@@ -0,0 +1,187 @@
+% FILTFILT overrides the filtfilt function for analysis objects.
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% DESCRIPTION: FILTFILT overrides the filtfilt function for analysis objects.
+%              Applies the input digital IIR filter to the input analysis object
+%              forwards and backwards. If the input analysis object contains a
+%              time-series (tsdata) then the filter is applied using the normal
+%              recursion algorithm. The output analysis object contains a tsdata
+%              object.
+%
+%              If the input analysis object contains a frequency-series (fsdata)
+%              then the response of the filter is computed and then multiplied
+%              with the input frequency series. The output analysis object
+%              contains a frequency series.
+%
+% CALL:        >> [b, filt] = filtfilt(a,pl)
+%              >> b = filtfilt(a,pl)
+%
+% INPUTS:      pl   - a parameter list
+%              a    - input analysis object
+%
+% OUTPUTS:     filt - a copy of the input filter object with the
+%                     history values filled in.
+%              b    - output analysis object containing the filtered data.
+%
+% <a href="matlab:utils.helper.displayMethodInfo('ao', 'filtfilt')">Parameters Description</a>
+%
+% VERSION:     $Id: filtfilt.m,v 1.48 2011/05/12 13:20:42 luigi Exp $
+%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+function varargout = filtfilt(varargin)
+  
+  % Check if this is a call for parameters
+  if utils.helper.isinfocall(varargin{:})
+    varargout{1} = getInfo(varargin{3});
+    return
+  end
+  
+  import utils.const.*
+  utils.helper.msg(msg.PROC3, 'running %s/%s', mfilename('class'), mfilename);
+  
+  % Collect input variable names
+  in_names = cell(size(varargin));
+  for ii = 1:nargin,in_names{ii} = inputname(ii);end
+  
+  % Collect all AOs and plists
+  [as, ao_invars] = utils.helper.collect_objects(varargin(:), 'ao', in_names);
+  [pl, pl_invars] = utils.helper.collect_objects(varargin(:), 'plist', in_names);
+  [fbobjs, f_invars] = utils.helper.collect_objects(varargin(:), 'filterbank', in_names);
+  [fobj, f_invars] = utils.helper.collect_objects(varargin(:), 'ltpda_filter', in_names);
+  
+  % Make copies or handles to inputs
+  bs   = copy(as, nargout);
+  
+  % combine plists
+  pl = parse(pl, getDefaultPlist());
+  
+  
+  if isempty(fobj) && isempty(fbobjs)
+    fobj        = find(pl, 'filter');
+    if isa(fobj, 'filterbank')
+    fbobjs = fobj;
+    end
+    f_invars{1} = class(fobj);
+  end
+  
+  % check inputs
+  if ~isa(fobj, 'miir') && ~isa(fobj, 'mfir') && ~isa(fbobjs, 'filterbank')
+    error('### the filter input should be either an miir/mfir object or a filterbank object.');
+  end
+  
+  fobj_out = [];
+  fp = [];
+  
+  % Loop over AOs
+  for jj = 1:numel(bs)
+    
+    % Copy filter so we can change it
+    if ~isempty(fobj)
+      fp = copy(fobj, 1);
+    elseif ~isempty(fbobjs)
+      fp = copy(fbobjs, 1);
+    end
+    % keep the history to suppress the history of the intermediate steps
+    inhist = bs(jj).hist;
+    
+    if isa(bs(jj).data, 'tsdata')
+      %------------------------------------------------------------------------
+      %------------------------   Time-series filter   ------------------------
+      %------------------------------------------------------------------------
+      
+      %%%%%%%%%%%%%%%%%%%%%%%%%%%     filter    %%%%%%%%%%%%%%%%%%%%%%%%%%%
+      if isa(fp,'ltpda_filter')
+        % redesign if needed
+        fs = bs(jj).data.fs;
+        if fs ~= fp.fs 
+          warning('!!! Filter is designed for a different sample rate of data.');
+          % Adjust/redesign if this is a standard filter
+          fp = redesign(fp, fs);
+        end
+        % apply filter
+        if isa(fp, 'miir')
+          bs(jj).data.y = filtfilt(fp.a, fp.b, bs(jj).data.y);
+        elseif isa(fp, 'mfir');
+          bs(jj).data.y = filtfilt(fp.a, 1, bs(jj).data.y);
+        else
+          error('### Unknown filter object [%s]', class(fp));
+        end
+        % set y-units = yunits.*ounits./iunits
+        bs(jj).data.setYunits(bs(jj).data.yunits.*fp.ounits./fp.iunits);
+        
+        %%%%%%%%%%%%%%%%%%%%%%%%%%%     filter bank     %%%%%%%%%%%%%%%%%%%%%%%%%%%
+      elseif isa(fp,'filterbank')
+        % redesign not implemented for filterbank
+        %%%
+        % utils.math routine to apply filtfilt properly
+        bs(jj).data.y = utils.math.filtfilt_filterbank(bs(jj),fp);
+        % not setting units yet
+        %%%
+      end
+      
+    elseif isa(bs(jj).data, 'fsdata')
+      %------------------------------------------------------------------------
+      %----------------------   Frequency-series filter   ---------------------
+      %------------------------------------------------------------------------
+      
+      % apply filter
+      fil_resp = resp(fp, plist('f', bs(jj)));
+      bs(jj)    = bs(jj).*fil_resp.*conj(fil_resp);
+    else
+      error('### unknown data type.');
+    end
+    
+    
+    % name for this object
+    bs(jj).name = sprintf('%s(%s)', fp.name, ao_invars{jj});
+    % add history
+    bs(jj).addHistory(getInfo('None'), pl, ao_invars(jj), [bs(jj).hist fp.hist]);
+    % clear errors
+    bs(jj).clearErrors;
+    % Collect the filters for the output
+    fobj_out = [fobj_out, fp];
+  end
+  
+  % Set outputs
+  if nargout == 1
+    varargout{1} = bs;
+  elseif nargout == 2
+    varargout{1} = bs;
+    varargout{2} = fobj_out;
+  elseif nargout > 2
+    error('### wrong number of output arguments.');
+  end
+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.sigproc, '$Id: filtfilt.m,v 1.48 2011/05/12 13:20:42 luigi Exp $', sets, pls);
+end
+
+%--------------------------------------------------------------------------
+% Get Default Plist
+%--------------------------------------------------------------------------
+function plout = getDefaultPlist()
+  persistent pl;  
+  if exist('pl', 'var')==0 || isempty(pl)
+    pl = buildplist();
+  end
+  plout = pl;  
+end
+
+function pl = buildplist()
+  pl = plist({'filter', 'The filter to apply to the data.'},  paramValue.EMPTY_STRING);
+end
+
+