--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/m-toolbox/classes/@ao/filter.m	Wed Nov 23 19:22:13 2011 +0100
@@ -0,0 +1,351 @@
+% FILTER overrides the filter function for analysis objects.
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% DESCRIPTION: FILTER overrides the filter function for analysis objects.
+%              Applies the input digital IIR/FIR filter to the input analysis
+%              object. 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] = filter(a,pl)
+%              >> [b, filt] = filter(a,filt,pl)
+%              >> b = filter(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.
+%                     (only possible if the ouput is a single AO)
+%              b    - output analysis object containing the filtered data.
+%
+% PROCINFO:    The input filter object with the history values filled in are
+%              always stored with a plist in the 'procinfo' property of the AO.
+%              The key of the plist to get the filter is 'Filter'.
+%
+%
+% <a href="matlab:utils.helper.displayMethodInfo('ao', 'filter')">Parameters Description</a>
+%
+% VERSION:     $Id: filter.m,v 1.86 2011/04/08 08:56:14 hewitson Exp $
+%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+function varargout = filter(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);
+  [fobjs, f_invars] = utils.helper.collect_objects(varargin(:), 'ltpda_filter', in_names);
+  [fbobjs, fb_invars] = utils.helper.collect_objects(varargin(:), 'filterbank', in_names);
+  [mobjs, m_invars] = utils.helper.collect_objects(varargin(:), 'matrix', in_names);
+
+  % Make copies or handles to inputs
+  bs   = copy(as, nargout);
+
+  % combine plists
+  pl = parse(pl, getDefaultPlist());
+  
+  % Filter with a filterbank object or a matrix
+  if ~isempty(fbobjs)
+    fobjs = fbobjs.filters;
+    pl.pset('bank', fbobjs.type);
+  elseif ~isempty(mobjs)
+    fobjs = mobjs.objs;
+    % check we do not have more than one object into the matrix, if this is
+    % the case the problem is considered a N-dimensional filtering problem
+    % that can be solved by matrix/filter
+    if numel(mobjs.objs)>1
+      error(['### Filter matrix has more than one object. '...
+        'This seems to be a N-dimensional filtering problem that has to be solved with matrix/filter. '...
+        'Type help matrix/filter for more information ###']);
+    end
+    if isa(fobjs,'filterbank') % in case of filterbanks
+      pl.pset('bank', fobjs.type);
+      fobjs = fobjs.filters;  
+    end
+  end
+
+  if isempty(fobjs)
+    fobjs = find(pl, 'filter');
+    % check if we have filterbank or matrix
+    if isa(fobjs,'filterbank') % in case of filterbank
+      pl.pset('bank', fobjs.type);
+      fobjs = fobjs.filters;
+    elseif isa(fobjs,'matrix') % in case of matrix
+      fobjs = fobjs.objs;
+      % check we do not have more than one object into the matrix, if this is
+      % the case the problem is considered a N-dimensional filtering problem
+      % that can be solved by matrix/filter
+      if numel(fobjs)>1
+        error(['### Filter matrix has more than one object. '...
+          'This seems to be a N-dimensional filtering problem that has to be solved with matrix/filter. '...
+          'Type help matrix/filter for more information ###']);
+      end
+      if isa(fobjs,'filterbank') % in case of filterbanks
+        pl.pset('bank', fobjs.type);
+        fobjs = fobjs.filters;  
+      end
+    end
+  end
+  
+  
+  % decide to initialize or not
+  init = utils.prog.yes2true(find(pl, 'initialize'));
+
+  % check inputs
+  if ~isa(fobjs, 'miir') && ~isa(fobjs, 'mfir')
+    error('### the filter input should be an miir/mfir object.');
+  end
+
+  if numel(bs) > 1 && nargout > 1
+    error('### It is only possible to output a bank of filters when applied to a single AO.');
+  end
+
+  for j=1:numel(bs)
+
+    % Copy filter so we can change it
+    fobjs_copy = copy(fobjs, 1);
+    % keep the history to suppress the history of the intermediate steps
+    inhist = bs(j).hist;
+
+    if isa(bs(j).data, 'tsdata')
+      %------------------------------------------------------------------------
+      %------------------------   Time-series filter   ------------------------
+      %------------------------------------------------------------------------
+      % get input data
+      if isa(fobjs_copy, 'mfir')
+        % apply filter
+        utils.helper.msg(msg.PROC1, 'filtering with FIR filter');
+        [bs(j).data.y, Zf] = filter(fobjs_copy.a, 1, bs(j).data.y, fobjs_copy.histout);
+        % remove group delay
+        if strcmpi(find(pl, 'gdoff'), 'no')
+          gd = floor(fobjs_copy.gd);
+          bs(j).data.setXY(bs(j).data.getX(1:end-gd),bs(j).data.getY(1+gd:end));
+          bs(j).data.collapseX;
+        end
+        % set units of the output data as we go
+        bs(j).data.setYunits(bs(j).data.yunits.*fobjs_copy.ounits./fobjs_copy.iunits);
+
+      else %if isa(fobjs_copy, 'miir')
+        utils.helper.msg(msg.PROC1, 'filtering with IIR filter');
+        % initialise data vector
+        bank = find(pl, 'bank');
+        switch lower(bank)
+          case 'parallel'
+            y = zeros(size(bs(j).data.getY));
+          case 'serial'
+            y = ones(size(bs(j).data.getY));
+          otherwise
+            error('### Unknown filter bank option. Choose ''serial'' or ''parallel''.');
+        end
+        % Loop over filters
+        iu = fobjs_copy(1).iunits;
+        ou = fobjs_copy(1).ounits;        
+        for ff = 1:numel(fobjs_copy)
+
+          % check sample rate
+          if bs(j).data.fs ~= fobjs_copy(ff).fs
+            warning('!!! Filter is designed for a different sample rate of data.');
+            % Adjust/redesign if this is a standard filter
+            fobjs_copy(ff) = fobjs_copy(ff).redesign(bs(j).data.fs);
+          end
+                    
+          % Choose filtering type
+          switch lower(bank)
+            
+            case 'parallel'
+              % check units
+              if iu ~= fobjs_copy(ff).iunits
+                error('### Input units of each filter must match for a parallel filter bank.');
+              end
+              if ou ~= fobjs_copy(ff).ounits
+                error('### Output units of each filter must match for a parallel filter bank.');
+              end
+              % Initialise the state to avoid transients if necessary and
+              % explicitely required
+              if ((~any(fobjs_copy(ff).histout) || isempty(fobjs_copy(ff).histout)) && init)
+                zi = utils.math.iirinit(fobjs_copy(ff).a,fobjs_copy(ff).b);
+                % setting new histout
+                fobjs_copy(ff).setHistout(zi*bs(j).data.y(1));
+              end
+              % filter data
+              [yf, Zf] = filter(fobjs_copy(ff).a, fobjs_copy(ff).b, bs(j).data.y, fobjs_copy(ff).histout);
+              if ~isequal(size(yf),size(y))
+                yf = yf.';
+              end
+              y = y + yf;
+              
+            case 'serial'
+              if ff == 1
+                y = bs(j).data.y;
+              end
+              % Initialise the state to avoid transients if necessary
+              if ~any(fobjs_copy(ff).histout) || isempty(fobjs_copy(ff).histout)
+                zi = utils.math.iirinit(fobjs_copy(ff).a,fobjs_copy(ff).b);
+                % setting new histout
+                fobjs_copy(ff).setHistout(zi*y(1));
+              end
+              % filter data
+              [yf, Zf] = filter(fobjs_copy(ff).a, fobjs_copy(ff).b, y, fobjs_copy(ff).histout);
+              if ~isequal(size(yf),size(y))
+                y = yf.';
+              else
+                y = yf;
+              end
+              % set units of the output data as we go
+              bs(j).data.setYunits(bs(j).data.yunits.*fobjs_copy(ff).ounits./fobjs_copy(ff).iunits);
+            otherwise
+              error('### Unknown filter bank option. Choose ''serial'' or ''parallel''.');
+          end
+          % set filter output history
+          fobjs_copy(ff).setHistout(Zf);
+        end % End loop over filters
+        
+        % set output data
+        bs(j).data.setY(y);
+        % clear errors
+        bs(j).clearErrors;
+        
+        % if this was a parallel filter bank, we should set the units now
+        if strcmpi(bank, 'parallel')
+          % set units of the output data
+          bs(j).data.setYunits(bs(j).data.yunits.*fobjs_copy(1).ounits./fobjs_copy(1).iunits);
+          bs(j).data.yunits.simplify;
+        end
+        
+      end % End filter type
+
+    elseif isa(bs(j).data, 'fsdata')
+      %------------------------------------------------------------------------
+      %----------------------   Frequency-series filter   ---------------------
+      %------------------------------------------------------------------------
+
+      utils.helper.msg(msg.PROC1, 'filtering with %s filter', upper(class(fobjs_copy)));
+
+      % apply filter
+      if numel(fobjs_copy)==1
+        bs(j) = bs(j).*resp(fobjs_copy, plist('f', bs(j).x));
+      else
+        bank = find(pl, 'bank');
+        iu = fobjs_copy(1).iunits;
+        ou = fobjs_copy(1).ounits;
+        switch lower(bank)
+          case 'parallel'
+            sfr = resp(fobjs_copy, plist('f', bs(j).x));
+            fr = sfr(1);
+            for jj = 2:numel(fobjs_copy)
+              if iu ~= fobjs_copy(jj).iunits
+                error('### Input units of each filter must match for a parallel filter bank.');
+              end
+              if ou ~= fobjs_copy(jj).ounits
+                error('### Output units of each filter must match for a parallel filter bank.');
+              end
+              fr = fr + sfr(jj);
+            end
+            bs(j) = bs(j).*fr;
+          case 'serial'
+            sfr = resp(fobjs_copy, plist('f', bs(j).x));
+            fr = sfr(1);
+            for jj = 2:numel(fobjs_copy)
+              fr = fr.*sfr(jj);
+            end
+            bs(j) = bs(j).*fr;
+        end
+      end
+      
+    else
+      error('### unknown data type.');
+    end
+
+    % name for this object
+    bs(j).name = sprintf('%s(%s)', fobjs_copy.name, ao_invars{j});
+    % Collect the filters into procinfo
+    bs(j).procinfo = plist('filter', fobjs_copy);
+    % add history
+    bs(j).addHistory(getInfo('None'), pl, ao_invars(j), [inhist fobjs_copy(:).hist]);
+  end
+
+  % Set outputs
+  if nargout == 1
+    varargout{1} = bs;
+  elseif nargout == 2
+    varargout{1} = bs;
+    varargout{2} = fobjs_copy;
+  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: filter.m,v 1.86 2011/04/08 08:56:14 hewitson 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
+  p = param({'filter', 'The filter(s) to apply to the data.'}, paramValue.EMPTY_STRING);
+  pl.append(p);
+  
+  % GDoff
+  p = param({'GDOFF', 'Switch off correction for group delay.'}, paramValue.YES_NO);
+  p.val.setValIndex(2);
+  pl.append(p);
+  
+  % Bank
+  p = param({'bank', 'Specify what type of filter bank is being applied.'}, {1, {'parallel', 'serial'}, paramValue.SINGLE});
+  pl.append(p);
+  
+  % Initialize
+  p = param({'initialize', 'Initialize the filter to avoid startup transients.'}, {1, {false, true}, paramValue.SINGLE});
+  pl.append(p);
+  
+end
+
+% PARAMETERS:  filter - the filter object to use to filter the data
+%              bank   - For IIR filtering, specify if the bank of filters
+%                       is intended to be 'serial' or 'parallel' [default]
+%              initialize - true or false if you want the filter being
+%                           automatically initialized or not.