Mercurial > hg > smallbox
view solvers/SMALL_MP.m @ 182:f8bc99a5470c danieleb
Added test for audio buffer function
author | Daniele Barchiesi <daniele.barchiesi@eecs.qmul.ac.uk> |
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date | Mon, 09 Jan 2012 12:58:00 +0000 |
parents | 8e660fd14774 |
children |
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function [A]=SMALL_MP(Dict,X, m, maxNumCoef, errorGoal, varargin) %% Implementation of Matching Pursuit algorithm % Sparse coding of a group of signals based on a given % dictionary and specified number of atoms to use. % input arguments: Dict - the dictionary % X - the signals to represent % m - number of atoms in Dictionary % errorGoal - the maximal allowed representation error for % each signal. % % optional: if Dict is function handle then Transpose Dictionary % handle needs to be specified. % % % Centre for Digital Music, Queen Mary, University of London. % This file copyright 2009 Ivan Damnjanovic. % % This program is free software; you can redistribute it and/or % modify it under the terms of the GNU General Public License as % published by the Free Software Foundation; either version 2 of the % License, or (at your option) any later version. See the file % COPYING included with this distribution for more information. % %% % This Dictionary check is based on Thomas Blumensath work in sparsify 0_4 greedy solvers explicitD=0; if isa(Dict,'float') D =@(z) Dict*z; Dt =@(z) Dict'*z; explicitD=1; elseif isobject(Dict) D =@(z) Dict*z; Dt =@(z) Dict'*z; elseif isa(Dict,'function_handle') try DictT=varargin{1}; if isa(DictT,'function_handle'); D=Dict; Dt=DictT; else error('If Dictionary is a function handle,Transpose Dictionary also needs to be a function handle. '); end catch error('If Dictionary is a function handle, Transpose Dictionary needs to be specified. Exiting.'); end else error('Dictionary is of unsupported type. Use explicit matrix, function_handle or object. Exiting.'); end %% [n,P]=size(X); %E2 = errorGoal^2; A = sparse(m,size(X,2)); for k=1:1:P, x = X(:,k); residual=x; indx = []; j=0; currResNorm = norm(residual); errGoal=errorGoal*currResNorm; a = zeros(m,1); while currResNorm>errGoal && j < maxNumCoef, j = j+1; dir=Dt(residual); [tmp__, pos]=max(abs(dir)); indx(j)=pos; a(pos)=dir(pos); e = zeros(m,1); e(pos) = 1; residual=residual-D(e)*a(pos); currResNorm = norm(residual); end; if (~isempty(indx)) A(indx,k)=a(indx); end end; return;