Mercurial > hg > ltpda
diff m-toolbox/classes/@ao/mcmc.m @ 0:f0afece42f48
Import.
author | Daniele Nicolodi <nicolodi@science.unitn.it> |
---|---|
date | Wed, 23 Nov 2011 19:22:13 +0100 |
parents | |
children |
line wrap: on
line diff
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/m-toolbox/classes/@ao/mcmc.m Wed Nov 23 19:22:13 2011 +0100 @@ -0,0 +1,233 @@ +% MCMC estimates paramters using a Monte Carlo Markov Chain. +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +% +% DESCRIPTION: MCMC estimate the parameters of a given model given +% inputs, outputs and noise using a Metropolis algorithm. +% It handles (1 input / 1 output) systems, (2 input / 1 output) systems, +% and (2 input / 2 output) systems. +% +% CALL: b = mcmc(in,out,pl) +% +% INPUTS: out - analysis objects with measured outputs +% +% pl - parameter list +% +% OUTPUTS: b - pest object contatining estimate information +% +% <a href="matlab:utils.helper.displayMethodInfo('ao', 'mcmc')">Parameters Description</a> +% +% VERSION: $Id: mcmc.m,v 1.24 2011/11/16 15:21:13 nikos Exp $ +% +% References: "Catching supermassive black holes binaries without a net" +% N.J. Cornish, E.K. Porter, Phys.Rev.D 75, 021301, 2007 +% +% TODO: multiple chain option not implemented yet +% metropolis/hastings not implemented +% +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +function varargout = mcmc(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); + + % Method can not be used as a modifier + if nargout == 0 + error('### mcmc 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 smodels 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 + out = copy(as, nargout); + + % Combine plists + pl = parse(pl, getDefaultPlist); + + + % Get parameters from plist + mtxin = find(pl,'input'); + noi = find(pl,'noise'); + mdlin = find(pl,'model'); + + % Decide on a deep copy or a modify + in = copy(mtxin, nargout); + mdl = copy(mdlin, nargout); + + numexp = numel(in(1,:)); + numchannels_in = numel(in(:,1)); + numchannels_out = numel(out(:,1)); + + if (numel(in) ~= numel(out)) + error('### Dimensions of input and output must be equal.'); + end + + % Redefining the ao inputs as matrix objects + for ii = 1:numexp + matin(ii) = matrix(in(:,ii),plist('shape',[numchannels_in 1])); + matout(ii) = matrix(out(:,ii),plist('shape',[numchannels_in 1])); + matnoise(ii) = matrix(noi(:,ii),plist('shape',[numchannels_in 1])); + end + + switch class(mdl) + case 'smodel' + matmodel = matrix(mdl); + case 'ssm' + matmodel = mdl; + case 'matrix' + matmodel = mdl; + end + + pl = pset(pl,'model',matmodel,'input',matin,'noise',matnoise); + mcmc_obj = mcmc(matout,pl); + + + % Set output + varargout{1} = mcmc_obj; + +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: mcmc.m,v 1.24 2011/11/16 15:21:13 nikos 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(); + + % N + p = param({'N','number of samples of the chain.'}, paramValue.DOUBLE_VALUE(1000)); + pl.append(p); + + % Sigma + p = param({'cov','covariance of the gaussian jumping distribution.'}, paramValue.DOUBLE_VALUE(1e-4)); + pl.append(p); + + % Param + p = param({'Fitparams','A cell array of evaluated parameters.'}, paramValue.EMPTY_DOUBLE); + pl.append(p); + + % Input + p = param({'input','A matrix array of input signals.'}, paramValue.EMPTY_STRING); + pl.append(p); + + % Frequencies + p = param({'frequencies','Range of frequencies where the analysis is performed. If an array, only first and last are used'}, paramValue.EMPTY_DOUBLE); + pl.append(p); + + % Noise + p = param({'noise','An array of noise spectrum (PSD) used to compute the likelihood.<ul>', ... + '<li>1 channel - Input one object</li>', ... + '<li>2 channel - Input four objects defining the power spectrum matrix </li>',... + '</ul>'}, paramValue.EMPTY_STRING); + pl.append(p); + + % Model + p = param({'model','An array of models.',... + '<li>1 input / 1 output - Input one object</li>', ... + '<li>2 input / 1 output - Input two objects</li>', ... + '<li>2 channel (2 input/ 2 output) - Input four objects defining the transfer function matrix </li>',... + '</ul>'}, paramValue.EMPTY_STRING); + pl.append(p); + + % Search + p = param({'search','Set to true to use bigger jumps in parameter space during annealing and cool down.'}, paramValue.TRUE_FALSE); + pl.append(p); + + % Simplex + p = param({'simplex','Set to true to perform a simplex search to find the starting parameters of the MCMC chain.'}, paramValue.TRUE_FALSE); + pl.append(p); + + % heat + p = param({'heat','The heat index flattening likelihood surface during annealing.'}, paramValue.DOUBLE_VALUE(1)); + pl.append(p); + + % Tc + p = param({'Tc','An array of two values setting the initial and final value for the cooling down.'}, paramValue.EMPTY_DOUBLE); + pl.append(p); + + % x0 + p = param({'x0','The proposed initial values.'}, paramValue.EMPTY_DOUBLE); + pl.append(p); + + % jumps + p = param({'jumps','An array of four numbers setting the rescaling of the covariance matrix during the search phase.',... + 'The first value is the one applied by default, the following thhree apply just when the chain sample is',... + 'mod(10), mod(25) and mod(100) respectively.'}, paramValue.EMPTY_DOUBLE); + pl.append(p); + + % plot + p = param({'plot','Select indexes of the parameters to be plotted.'}, paramValue.EMPTY_DOUBLE); + pl.append(p); + + % debug + p = param({'debug','Set to true to get debug information of the MCMC process.'}, paramValue.FALSE_TRUE); + pl.append(p); + + p = param({'prior','Mean, sigma and normalization factor for priors. Still under test'}, paramValue.EMPTY_STRING); + pl.append(p); + + p = param({'anneal',['Choose type of annealing during sampling. Default value is ',... + 'simulated annealing. Choose "thermo" for annealing with a thermostat.',... + ' SNR is computed and if it is larger than a fixed value SNR0 (provided also in the plist), ',... + 'then the chains are heated by a factor of (SNR(1)/SNR0)^2. Choosing "simple" ',... + 'the deviation of the loglikelihood of every 10 points in the chains is stored. If this deviation ',... + 'is larger or smaller than two fixed values the chains are cooled or heated respectively.']}, {1, {'simul','thermo', 'simple'}, paramValue.SINGLE}); + pl.append(p); + + p = param({'SNR0','Fixed value for thermostated annealing.'}, {1, {200}, paramValue.OPTIONAL}); + pl.append(p); + + p = param({'DeltaL',['Deviation of Loglikelihood for 10 points of the chains. Used for',... + 'the "simple" choice of annealing with a thermostat.']}, {1, {[100 600 2 3]}, paramValue.OPTIONAL}); + pl.append(p); + +end + + +% PARAMETERS: J - number of chains to compute. +% sigma - dispersion of the jumping distribution. +% range - range where the parameteters are sampled. +% param - a cell array of evaluated parameters (from the +% smodel). +% Tc - an array with two values (default: 0, i.e. no annealing). +% heat - heat index flattening likelihood surface (default: 1) +% x0 - proposed initial values, if empty selected randomly. +% (default: empty) + +