EMD与EEMD程序..docVIP

%%%%%%%%%%%载入信号 x=load(1.txt);%产生信号 N=length(x); %采样点数 fs=2000; %采样频率 dt=1/fs; %采样时间间隔 t=(0:N-1)*dt; %产生时间序列 %%%%%%%%EMD imf=emd(x); % EMD.M (EMD程序) % G. Rilling, July 2002 % % computes EMD (Empirical Mode Decomposition) according to: % % N. E. Huang et al., The empirical mode decomposition and the % Hilbert spectrum for non-linear and non stationary time series analysis, % Proc. Royal Soc. London A, Vol. 454, pp. 903-995, 1998 % % with variations reported in: % % G. Rilling, P. Flandrin and P. Gon?alvès % On Empirical Mode Decomposition and its algorithms % IEEE-EURASIP Workshop on Nonlinear Signal and Image Processing % NSIP-03, Grado (I), June 2003 % % stopping criterion for sifting : % at each point : mean amplitude threshold2*envelope amplitude % % mean of boolean array ((mean amplitude)/(envelope amplitude) threshold) tolerance % % |#zeros-#extrema|=1 % % inputs: - x : analysed signal (line vector) % - t (optional) : sampling times (line vector) (default : 1:length(x)) % - stop (optional) : threshold, threshold2 and tolerance (optional) % for sifting stopping criterion % default : [0.05,0.5,0.05] % - tst (optional) : if equals to 1 shows sifting steps with pause % if equals to 2 no pause % % outputs: - imf : intrinsic mode functions (last line = residual) % - ort : index of orthogonality % - nbits : number of iterations for each mode % % calls: - extr (finds extrema and zero-crossings) % - io : computes the index of orthogonality function [imf,ort,nbits] = emd(x,t,stop,tst); % default for stopping defstop = [0.05,0.5,0.05]; if(nargin==1) t = 1:length(x); stop = defstop; tst = 0; end if(nargin==2) stop = defstop; tst = 0; end if (nargin==3) tst=0; end S = size(x); if ((S(1) 1) (S(2) 1)) | (length(S) 2) error(x must have only one row or one column) end