ECG信号的经验模态分解(EMD)MATLAB仿真【包括程序，注释，参考文献，操作步骤】

function [x,t,sd,sd2,tol,MODE_COMPLEX,ndirs,display_sifting,sdt,sd2t,r,imf,k,nbit,NbIt,MAXITERATIONS,FIXE,FIXE_H,MAXMODES,INTERP,mask] = init(varargin) x = varargin{1}; if nargin == 2 if isstruct(varargin{2}) inopts = varargin{2}; else error('when using 2 arguments the first one is the analyzed signal X and the second one is a struct object describing the options') end elseif nargin > 2 try inopts = struct(varargin{2:end}); catch error('bad argument syntax') end end % default for stopping defstop = [0.05,0.5,0.05]; opt_fields = {'t','stop','display','maxiterations','fix','maxmodes','interp','fix_h','mask','ndirs','complex_version'}; defopts.stop = defstop; defopts.display = 0; defopts.t = 1:max(size(x)); defopts.maxiterations = 2000; defopts.fix = 0; defopts.maxmodes = 0; defopts.interp = 'spline'; defopts.fix_h = 0; defopts.mask = 0; defopts.ndirs = 4; defopts.complex_version = 2; opts = defopts; if(nargin==1) inopts = defopts; elseif nargin == 0 error('not enough arguments') end names = fieldnames(inopts); for nom = names' if ~any(strcmpi(char(nom), opt_fields)) error(['bad option field name: ',char(nom)]) end if ~isempty(eval(['inopts.',char(nom)])) % empty values are discarded eval(['opts.',lower(char(nom)),' = inopts.',char(nom),';']) end end t = opts.t; stop = opts.stop; display_sifting = opts.display; MAXITERATIONS = opts.maxiterations; FIXE = opts.fix; MAXMODES = opts.maxmodes; INTERP = opts.interp; FIXE_H = opts.fix_h; mask = opts.mask; ndirs = opts.ndirs; complex_version = opts.complex_version; if ~isvector(x) error('X must have only one row or one column') end if size(x,1) > 1 x = x.'; end if ~isvector(t) error('option field T must have only one row or one column') end if ~isreal(t) error('time instants T must be a real vector') end if size(t,1) > 1 t = t'; end if (length(t)~=length(x)) error('X and option field T must have the same length') end if ~isvector(stop) || length(stop) > 3 error('option field STOP must have only one row or one column of max three elements') end if ~all(isfinite(x)) error('data elements must be finite') end if size(stop,1) > 1 stop = stop'; end L = length(stop); if L < 3 stop(3)=defstop(3); end if L < 2 stop(2)=defstop(2); end if ~ischar(INTERP) || ~any(strcmpi(INTERP,{'linear','cubic','spline'})) error('INTERP field must be ''linear'', ''cubic'', ''pchip'' or ''spline''') end %special procedure when a masking signal is specified if any(mask) if ~isvector(mask) || length(mask) ~= length(x) error('masking signal must have the same dimension as the analyzed signal X') end if size(mask,1) > 1 mask = mask.'; end opts.mask = 0; imf1 = emd(x+mask,opts); imf2 = emd(x-mask,opts); if size(imf1,1) ~= size(imf2,1) warning('emd:warning',['the two sets of IMFs have different sizes: ',int2str(size(imf1,1)),' and ',int2str(size(imf2,1)),' IMFs.']) end S1 = size(imf1,1); S2 = size(imf2,1); if S1 ~= S2 if S1 < S2 tmp = imf1; imf1 = imf2; imf2 = tmp; end imf2(max(S1,S2),1) = 0; end imf = (imf1+imf2)/2; end sd = stop(1); sd2 = stop(2); tol = stop(3); lx = length(x); sdt = sd*ones(1,lx); sd2t = sd2*ones(1,lx); if FIXE MAXITERATIONS = FIXE; if FIXE_H error('cannot use both ''FIX'' and ''FIX_H'' modes') end end MODE_COMPLEX = ~isreal(x)*complex_version; if MODE_COMPLEX && complex_version ~= 1 && complex_version ~= 2 error('COMPLEX_VERSION parameter must equal 1 or 2') end % number of extrema and zero-crossings in residual ner = lx; nzr = lx; r = x; if ~any(mask) % if a masking signal is specified "imf" already exists at this stage imf = []; end k = 1; % iterations counter for extraction of 1 mode nbit=0; % total iterations counter NbIt=0; end