diff m-toolbox/classes/@ao/dsmean.m @ 0:f0afece42f48

Import.
author Daniele Nicolodi <nicolodi@science.unitn.it>
date Wed, 23 Nov 2011 19:22:13 +0100
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/m-toolbox/classes/@ao/dsmean.m	Wed Nov 23 19:22:13 2011 +0100
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+% DSMEAN performs a simple downsampling by taking the mean of every N samples.
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% DESCRIPTION: DSMEAN performs a simple downsampling by taking the mean of
+%              every N samples. The downsample factor (N) is taken as
+%              round(fs/fsout). The original vector is then truncated to a
+%              integer number of segments of length N. It is the reshaped
+%              to N x length(y)/N. Then the mean is taken.
+%
+% CALL:        b = dsmean(a, pl)
+%
+% <a href="matlab:utils.helper.displayMethodInfo('ao', 'dsmean')">Parameters Description</a>
+%
+% VERSION:     $Id: dsmean.m,v 1.23 2011/05/11 08:42:19 mauro Exp $
+%
+% HISTORY:     20-04-08 M Hewitson
+%                 Creation
+%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+function varargout = dsmean(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              = utils.helper.collect_objects(varargin(:), 'plist', in_names);
+
+  % Decide on a deep copy or a modify
+  bs = copy(as, nargout);
+
+  % Combine plists
+  pl = parse(pl, getDefaultPlist);
+
+  % Extract necessary parameters
+  fsout = find(pl, 'fsout');
+
+  % Loop over input AOs
+  for jj = 1:numel(bs)
+    if ~isa(bs(jj).data, 'tsdata')
+      warning('!!! Can only downsample time-series (tsdata) objects. Skipping AO %s', ao_invars{j});
+    else
+      % downsample factor
+      dsf = round(bs(jj).data.fs/fsout);
+      if dsf < 1
+        error('### I can''t downsample - the sample rate is already lower than the requested.');
+      elseif dsf>1
+        % Do Y data
+        n = floor(length(bs(jj).data.y) / dsf);
+        y = bs(jj).data.y(1:n*dsf);
+        % reshape and take mean
+        bs(jj).data.setY(mean(reshape(y, dsf, length(y)/dsf)));
+        
+        % If we have an x we should resample it
+        if ~isempty(bs(jj).data.x)
+          x = bs(jj).data.x(1:n*dsf);
+          % reshape and take mean
+          bs(jj).data.setX(mean(reshape(x, dsf, length(x)/dsf)));
+        else
+          % otherwise we need to adjust t0
+          bs(jj).data.setT0(bs(jj).data.t0 + dsf/(2*bs(jj).data.fs));
+        end
+      end
+      % Build output AO
+      bs(jj).data.setFs(fsout);
+      bs(jj).name = sprintf('dsmean(%s)', ao_invars{jj});
+      % Add history
+      bs(jj).addHistory(getInfo('None'), pl, ao_invars(jj), bs(jj).hist);
+      % Clear the errors since they don't make sense anymore
+      clearErrors(bs(jj));
+    end
+  end
+
+  % Set output
+  varargout = utils.helper.setoutputs(nargout, bs);
+end
+
+%--------------------------------------------------------------------------
+% Get Info Object
+%--------------------------------------------------------------------------
+function ii = getInfo(varargin)
+  if nargin == 1 && strcmpi(varargin{1}, 'None')
+    sets = {};
+    pl   = [];
+  else
+    sets = {'Default'};
+    pl   = getDefaultPlist();
+  end
+  % Build info object
+  ii = minfo(mfilename, 'ao', 'ltpda', utils.const.categories.sigproc, '$Id: dsmean.m,v 1.23 2011/05/11 08:42:19 mauro Exp $', sets, pl);
+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({'fsout', 'The output sample rate.'}, {1, {10}, paramValue.OPTIONAL});
+end
+
+