Mercurial > hg > ltpda
diff m-toolbox/classes/@ao/spikecleaning.m @ 0:f0afece42f48
Import.
author | Daniele Nicolodi <nicolodi@science.unitn.it> |
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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/spikecleaning.m Wed Nov 23 19:22:13 2011 +0100 @@ -0,0 +1,214 @@ +% spikecleaning detects and corrects possible spikes in analysis objects +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +% +% DESCRIPTION: SPIKECLEANING detects spikes in the temperature data and +% replaces them by artificial values depending on the method chosen ('random', +% 'mean', 'previous'). +% Spikes are defined as singular samples with an (absolute) value +% higher than kspike times the standard deviation of the high-pass +% filtered (IIR filter) input AO. +% +% CALL: b = spikecleaning(a1, a2, ..., an, pl) +% +% INPUTS: aN - a list of analysis objects +% pl - parameter list +% +% OUTPUTS: b - a list of analysis objects with "spike values" removed +% and corrected +% +% <a href="matlab:utils.helper.displayMethodInfo('ao', 'spikecleaning')">Parameters Description</a> +% +% VERSION: $Id: spikecleaning.m,v 1.17 2011/04/08 08:56:16 hewitson Exp $ +% +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +function varargout=spikecleaning(varargin) + + %%% Check if this is a call for parameters + if utils.helper.isinfocall(varargin{:}) + varargout{1} = getInfo(varargin{3}); + return + end + + if nargout == 0 + error('### cat cannot be used as a modifier. Please give an output variable.'); + end + + % 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); + pli = utils.helper.collect_objects(varargin(:), 'plist', in_names); + + pls = parse(pli, getDefaultPlist()); + + % initialise output array + bo = []; + + % go through each input AO + for i=1:numel(as) + a = as(i); + d = a.data; + + % check this is a time-series object + if ~isa(d, 'tsdata') + error(' ### temperature spike detection requires tsdata (time-series) inputs.') + end + + %--- check input parameters + kspike = find(pls, 'kspike'); % kspike*sigma definition + method = find(pls, 'method'); % method of spike-values substitution + pls.pset('gain', 1); % gain of the filter + pls.pset('type', 'highpass'); % type of the filter + fs = plist(); + fs.append('fs', d.fs); + pls.combine(fs); % determination of the sampling frequency of the input AO + + % high-pass filtering data + xfiltered = filtfilt(a, miir(pls)); + + % standard deviation of the filtered data is calculated + nxfiltered = find(abs(xfiltered) < kspike*std(xfiltered)); + + xfiltered_2 = xfiltered.data.y(nxfiltered); + + std_xfiltered_2 = std(xfiltered_2); + + % spikes vector position is determined + nspike = find(abs(xfiltered) > kspike*std_xfiltered_2); + + % substitution of spike values starts here + xcleaned = a.data.y; + for j=1:length(nspike) + if nspike(j) <=2 % just in case a spike is detected in the 1st or 2nd sample + xcleaned(nspike(j)) = mean(xcleaned(1:50)); + else + if strcmp(method, 'random') % spike is substituted by a random value: N(0,std_xfiltered) + xcleaned(nspike(j)) = xcleaned(nspike(j)-1) + randn(1)*std_xfiltered_2; + elseif strcmp(method, 'mean') % spike is substituted by the mean if the two previous values + xcleaned(nspike(j)) = (xcleaned(nspike(j)-1) + xcleaned(nspike(j)-2))/2; + elseif strcmp(method, 'previous') % spike is substituted by the pervious value + xcleaned(nspike(j)) = xcleaned(nspike(j)-1); + end + end + end + + % create new output tsdata + ts = tsdata(xcleaned, d.fs); + ts.setYunits(d.yunits); + ts.setXunits(d.xunits); + + % % create new output history + % h = history(ALGONAME, VERSION, pls, a.hist); + % h = set(h, 'invars', invars); + + % make output analysis object + b = ao(ts); + b.name = sprintf('spikecleaning(%s)', ao_invars{i}); + b.addHistory(getInfo('None'), pls, ao_invars(i), as(i).hist); + + % add to output array + bo = [bo b]; + + end + + % Set output + if nargout == numel(bo) + % List of outputs + for ii = 1:numel(bo) + varargout{ii} = bo(ii); + end + else + % Single output + varargout{1} = bo; + end + +end + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +% Local Functions % +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +% +% FUNCTION: getInfo +% +% DESCRIPTION: Get Info Object +% +% HISTORY: 11-07-07 M Hewitson +% Creation. +% +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +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: spikecleaning.m,v 1.17 2011/04/08 08:56:16 hewitson Exp $', sets, pl); + ii.setModifier(false); +end + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +% +% FUNCTION: getDefaultPlist +% +% DESCRIPTION: Get Default Plist +% +% HISTORY: 11-07-07 M Hewitson +% Creation. +% +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +function plout = getDefaultPlist() + persistent pl; + if exist('pl', 'var')==0 || isempty(pl) + pl = buildplist(); + end + plout = pl; +end + +function pl = buildplist() + + pl = plist(); + + % kspike + p = param({'kspike', 'High values imply no correction of relative low amplitude spikes.'}, paramValue.DOUBLE_VALUE(3.3)); + pl.append(p); + + % fc + p = param({'fc', 'Frequency cut-off of the IIR filter.'}, paramValue.DOUBLE_VALUE(0.025)); + pl.append(p); + + % Order + p = param({'order', 'The order of the IIR filter.'}, paramValue.DOUBLE_VALUE(2)); + pl.append(p); + + % Ripple + p = param({'ripple', 'Specify the pass/stop-band ripple for bandpass/bandreject filters'}, ... + paramValue.DOUBLE_VALUE(0.5)); + pl.append(p); + + % Method + p = param({'method', 'The method used to replace the spike value.'}, {1, {'random', 'mean'}, paramValue.SINGLE}); + pl.append(p); + +end + +% PARAMETERES: 'kspike' - set the kspike value. High values imply +% not correction of relative low amplitude spike +% [default: 3.3] +% 'method' - method used to replace the spike value: 'random, +% 'mean', 'previous' [default:random] +% 'fc' - frequency cut-off of the IIR filter [default: 0.025] +% 'order' - order of the IIR filter [default: 2] +% 'ripple' - specify pass/stop-band ripple for bandpass +% and bandreject filters +% <<default: 0.5>> +%