--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/m-toolbox/classes/@ao/dft.m	Wed Nov 23 19:22:13 2011 +0100
@@ -0,0 +1,130 @@
+% DFT computes the DFT of the input time-series at the requested frequencies.
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% DESCRIPTION: DFT computes the DFT of the input time-series at the requested
+%              frequencies.
+%
+% CALL:        b = dft(a, pl)
+%
+% <a href="matlab:utils.helper.displayMethodInfo('ao', 'dft')">Parameters Description</a>
+%
+% VERSION:     $Id: dft.m,v 1.29 2011/04/08 08:56:13 hewitson Exp $
+%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+function varargout = dft(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
+  [as, ao_invars] = utils.helper.collect_objects(varargin(:), 'ao', in_names);
+  [pl, pl_invars] = utils.helper.collect_objects(varargin(:), 'plist', in_names);
+
+  % Make copies or handles to inputs
+  bs = copy(as, nargout);
+
+  % Combine plists
+  pl = parse(pl, getDefaultPlist);
+
+  % Loop over input AOs
+  for j=1:numel(bs)
+    if ~isa(bs(j).data, 'tsdata')
+      warning('!!! The DFT can only be computed on input time-series. Skipping AO %s', ao_invars{j});
+    else
+
+      % Extract necessary parameters
+      f = find(pl, 'f');
+      if isa(f, 'ao') && (isa(f.data, 'fsdata') || isa(f.data, 'xydata'))
+        f = f.data.getX;
+      end
+
+      % Compute f if necessary
+      if f == -1
+        f = linspace(0, bs(j).data.fs/2, length(bs(j).data.getY)/2+1);
+      end
+
+      % Compute DFT
+      fs  = bs(j).data.fs;
+      N   = length(bs(j).data.getY);
+      J   = -2*pi*1i.*[0:N-1]/fs;
+      dft = zeros(size(f));
+      for kk = 1:length(f)
+        dft(kk) = exp(f(kk)*J)*bs(j).data.getY;
+      end
+
+      % Make output fsdata AO
+      yunits = bs(j).data.yunits;
+      % Keep the data shape of the input AO
+      if size(bs(j).data.y,1) ~= 1
+        f   = f.';
+        dft = dft.';
+      end
+      bs(j).data = fsdata(f, dft, bs(j).data.fs);
+      bs(j).data.setXunits('Hz');
+      bs(j).data.setYunits(yunits./unit('Hz'));
+      % Set name
+      bs(j).name = sprintf('dft(%s)', ao_invars{j});
+      % Add history
+      bs(j).addHistory(getInfo('None'), pl, ao_invars(j), bs(j).hist);
+      % Clear the errors since they don't make sense anymore
+      clearErrors(bs(j));
+    end
+  end
+  
+
+  % Set output
+  if nargout == numel(bs)
+    % List of outputs
+    for ii = 1:numel(bs)
+      varargout{ii} = bs(ii);
+    end
+  else
+    % Single output
+    varargout{1} = bs;
+  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: dft.m,v 1.29 2011/04/08 08:56:13 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({'f', ['The vector of frequencies at which to compute the DFT <br>or an AO ' ...
+                    'where the x-axis is taken for the frequency values.']}, paramValue.DOUBLE_VALUE(-1));
+end
+
+