emd分解

%此版本为ALAN 版本的整合注释版 
 function imf = emd(x)
 % Empiricial Mode Decomposition (Hilbert-Huang Transform)
 % imf = emd(x)
 % Func : findpeaksx= transpose(x(:));%转置为行矩阵
 imf = [];while ~ismonotonic(x) %当x不是单调函数，分解终止条件
    x1 = x;
    sd = Inf;%均值
 %直到x1满足IMF条件，得c1
    while (sd > 0.1) | ~isimf(x1) %当标准偏差系数sd大于0.1或x1不是固有模态函数时，分量终止条件
       s1 = getspline(x1);%上包络线
       s2 = -getspline(-x1);%下包络线
       x2 = x1-(s1+s2)/2;%此处的x2为文章中的h
       
       sd = sum((x1-x2).^2)/sum(x1.^2);
       x1 = x2;
    end
    
    imf{end+1} = x1;
    x          = x-x1;
 endimf{end+1} = x;