Mercurial > hg > ltpda
diff m-toolbox/classes/@ao/firwhiten.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/firwhiten.m Wed Nov 23 19:22:13 2011 +0100 @@ -0,0 +1,220 @@ +% FIRWHITEN whitens the input time-series by building an FIR whitening filter. +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +% +% DESCRIPTION: FIRWHITEN whitens the input time-series by building an FIR +% whitening filter. The algorithm ultimately uses fir2() to +% build the whitening filter. +% +% ALGORITHM: +% 1) Make ASD of time-series +% 2) Perform running median to get noise-floor estimate (ao/smoother) +% 3) Invert noise-floor estimate +% 4) Call mfir() on noise-floor estimate to produce whitening filter +% 5) Filter data +% +% CALL: b = firwhiten(a, pl) % returns whitened time-series AOs +% [b, filts] = firwhiten(a, pl) % returns the mfir filters used +% [b, filts, nfs] = firwhiten(a, pl) % returns the noise-floor +% % estimates as fsdata AOs +% +% +% <a href="matlab:utils.helper.displayMethodInfo('ao', 'firwhiten')">Parameters Description</a> +% +% VERSION: $Id: firwhiten.m,v 1.29 2011/11/11 15:21:19 luigi Exp $ +% +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +function varargout = firwhiten(varargin) + + callerIsMethod = utils.helper.callerIsMethod; + + % 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 = utils.helper.collect_objects(varargin(:), 'plist', in_names); + + % Decide on a deep copy or a modify + bs = copy(as, nargout); + inhists = copy([as.hist],1); + + % combine plists + pl = parse(pl, getDefaultPlist()); + + % Extract necessary parameters + iNfft = find(pl, 'Nfft'); + bw = find(pl, 'bw'); + hc = find(pl, 'hc'); + swin = find(pl, 'win'); + order = find(pl, 'order'); + fwin = find(pl, 'FIRwin'); + Ntaps = find(pl, 'Ntaps'); + + % Loop over input AOs + filts = []; + nfs = []; + + for j=1:numel(bs) + if ~isa(bs(j).data, 'tsdata') + warning('!!! %s expects ao/tsdata objects. Skipping AO %s', mfilename, ao_invars{j}); + bs(j) = []; + else + % get Nfft + if iNfft < 0 || isempty(iNfft) + Nfft = length(bs(j).data.y); + else + Nfft = iNfft; + end + utils.helper.msg(msg.PROC1, 'building spectrum'); + % Make spectrum + axx = psd(bs(j), plist('Nfft', Nfft, 'Win', swin, 'Order', order, 'Scale', 'ASD')); + % make noise floor estimate + utils.helper.msg(msg.PROC1, 'estimating noise-floor'); + nxx = smoother(axx, plist('width', bw, 'hc', hc)); + % collect noise-floor estimates for output + nfs = [nfs nxx]; + % invert and make weights + w = 1./nxx; + % Make mfir object + utils.helper.msg(msg.PROC1, 'building filter'); + ff = mfir(w, plist('Win', fwin, 'N', Ntaps)); + % collect filters for output + filts = [filts ff]; + % Filter data + utils.helper.msg(msg.PROC1, 'filter data'); + filter(bs(j), ff); + % Set name + bs(j).name = sprintf('firwhiten(%s)', ao_invars{j}); + % add history + if ~callerIsMethod + bs(j).addHistory(getInfo('None'), pl, ao_invars(j), inhists(j)); + end + % clear errors + bs(j).clearErrors; + + end + end + + % Any errors are meaningless after this process, so clear them on both + % axes. + bs.clearErrors(plist('axis', 'xy')); + + % Set outputs + if nargout > 0 + varargout{1} = bs; + end + if nargout > 1 + varargout{2} = filts; + end + if nargout > 2 + varargout{3} = nfs; + end +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: firwhiten.m,v 1.29 2011/11/11 15:21:19 luigi Exp $', sets, pl); +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(); + + % Nfft + p = param({'Nfft', ['The number of points in the FFT used to estimate<br>'... + 'the power spectrum. If unspecified, this is calculated as Ndata/4.']}, paramValue.DOUBLE_VALUE(-1)); + pl.append(p); + + % BW + p = param({'bw', ['The bandwidth of the running median filter used to<br>'... + 'estimate the noise-floor.']}, {1, {20}, paramValue.OPTIONAL}); + pl.append(p); + + % HC + p = param({'hc', 'The cutoff used to reject outliers (0-1).'}, {1, {0.8}, paramValue.OPTIONAL}); + pl.append(p); + + % Win + p = param({'Win', 'Spectral window used in spectral estimation.'}, paramValue.WINDOW); + pl.append(p); + + % Order + p = param({'Order',['The order of segment detrending:<ul>', ... + '<li>-1 - no detrending</li>', ... + '<li>0 - subtract mean</li>', ... + '<li>1 - subtract linear fit</li>', ... + '<li>N - subtract fit of polynomial, order N</li></ul>']}, paramValue.DETREND_ORDER); + pl.append(p); + + % FIR win + p = param({'FIRwin', 'The window to use in the filter design.'}, paramValue.WINDOW); + pl.append(p); + + % Ntaps + p = param({'Ntaps', 'The length of the FIR filter to build.'}, {1, {256}, paramValue.OPTIONAL}); + pl.append(p); + +end + +% PARAMETERS: +% +% 'Ntaps' - the length of the FIR filter to build [default: 256]. +% 'FIRwin' - the window to use in the filter design. Pass a +% specwin object of the desired type and of any length. +% [default: Hanning] +% +% parameters passed to ltpda_pwelch() +% +% 'Nfft' - The number of points in the FFT used to estimate +% the power spectrum. +% [default: Ndata/4] +% 'Win' - Spectral window used in spectral estimation. +% [default: Kaiser -150dB] +% 'Order' - order of segment detrending: +% -1 - no detrending +% 0 - subtract mean [default] +% 1 - subtract linear fit +% N - subtract fit of polynomial, order N +% +% (Segment overlap is taken from the window function.) +% +% parameters passed to ltpda_nfest() +% +% 'bw' - The bandwidth of the running median filter used to +% estimate the noise-floor. +% [default: 20 samples] +% 'hc' - The cutoff used to reject outliers (0-1) +% [default: 0.8] +