+
−% DFT computes the DFT of the input time-series at the requested frequencies.
+
−%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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−%
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−% DESCRIPTION: DFT computes the DFT of the input time-series at the requested
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−%              frequencies.
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−%
+
−% CALL:        b = dft(a, pl)
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−%
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−% <a href="matlab:utils.helper.displayMethodInfo('ao', 'dft')">Parameters Description</a>
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−%
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−% VERSION:     $Id: dft.m,v 1.29 2011/04/08 08:56:13 hewitson Exp $
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−%
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−%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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−
+
−function varargout = dft(varargin)
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−
+
−  % Check if this is a call for parameters
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−  if utils.helper.isinfocall(varargin{:})
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−    varargout{1} = getInfo(varargin{3});
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−    return
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−  end
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−
+
−  import utils.const.*
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−  utils.helper.msg(msg.PROC3, 'running %s/%s', mfilename('class'), mfilename);
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−
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−  % Collect input variable names
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−  in_names = cell(size(varargin));
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−  for ii = 1:nargin,in_names{ii} = inputname(ii);end
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−
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−  % Collect all AOs
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−  [as, ao_invars] = utils.helper.collect_objects(varargin(:), 'ao', in_names);
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−  [pl, pl_invars] = utils.helper.collect_objects(varargin(:), 'plist', in_names);
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−
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−  % Make copies or handles to inputs
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−  bs = copy(as, nargout);
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−
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−  % Combine plists
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−  pl = parse(pl, getDefaultPlist);
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−
+
−  % Loop over input AOs
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−  for j=1:numel(bs)
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−    if ~isa(bs(j).data, 'tsdata')
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−      warning('!!! The DFT can only be computed on input time-series. Skipping AO %s', ao_invars{j});
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−    else
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−
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−      % Extract necessary parameters
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−      f = find(pl, 'f');
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−      if isa(f, 'ao') && (isa(f.data, 'fsdata') || isa(f.data, 'xydata'))
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−        f = f.data.getX;
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−      end
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−
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−      % Compute f if necessary
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−      if f == -1
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−        f = linspace(0, bs(j).data.fs/2, length(bs(j).data.getY)/2+1);
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−      end
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−
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−      % Compute DFT
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−      fs  = bs(j).data.fs;
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−      N   = length(bs(j).data.getY);
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−      J   = -2*pi*1i.*[0:N-1]/fs;
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−      dft = zeros(size(f));
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−      for kk = 1:length(f)
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−        dft(kk) = exp(f(kk)*J)*bs(j).data.getY;
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−      end
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−
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−      % Make output fsdata AO
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−      yunits = bs(j).data.yunits;
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−      % Keep the data shape of the input AO
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−      if size(bs(j).data.y,1) ~= 1
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−        f   = f.';
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−        dft = dft.';
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−      end
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−      bs(j).data = fsdata(f, dft, bs(j).data.fs);
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−      bs(j).data.setXunits('Hz');
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−      bs(j).data.setYunits(yunits./unit('Hz'));
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−      % Set name
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−      bs(j).name = sprintf('dft(%s)', ao_invars{j});
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−      % Add history
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−      bs(j).addHistory(getInfo('None'), pl, ao_invars(j), bs(j).hist);
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−      % Clear the errors since they don't make sense anymore
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−      clearErrors(bs(j));
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−    end
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−  end
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−  
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−
+
−  % Set output
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−  if nargout == numel(bs)
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−    % List of outputs
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−    for ii = 1:numel(bs)
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−      varargout{ii} = bs(ii);
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−    end
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−  else
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−    % Single output
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−    varargout{1} = bs;
+
−  end
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−end
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−
+
−%--------------------------------------------------------------------------
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−% Get Info Object
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−%--------------------------------------------------------------------------
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−function ii = getInfo(varargin)
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−  if nargin == 1 && strcmpi(varargin{1}, 'None')
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−    sets = {};
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−    pls  = [];
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−  else
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−    sets = {'Default'};
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−    pls  = getDefaultPlist;
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−  end
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−  % Build info object
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−  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
+
−%--------------------------------------------------------------------------
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−
+
−function plout = getDefaultPlist()
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−  persistent pl;  
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−  if exist('pl', 'var')==0 || isempty(pl)
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−    pl = buildplist();
+
−  end
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−  plout = pl;  
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−end
+
−
+
−function pl = buildplist()
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−  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
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−
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−