EMD分解问题，急~~~~~
本帖最后由 0208106224 于 2012-5-15 10:45 编辑下面这段程序我仿真出来是一组数据，现在我想让他呈现出emd图的形式要怎么弄？在后面我试着添加plot那些语句照样不行；各位大侠帮帮忙啊:'( 在emd分解后又如何去实现信号的去噪了？？？
% EMD:Emprical mode decomposition
%
% imf = emd(x,n)
%
% x - input signal (must be a column vector)
% n - number of intrinsic mode functions
%
% imf - Matrix of intrinsic mode functions (each as a row)
%
% See:Huang et al, Royal Society Proceedings on Math, Physical,
% and Engineering Sciences, vol. 454, no. 1971, pp. 903-995,
% 8 March 1998
%
% Author: Ivan Magrin-Chagnolleau<ivan@ieee.org>
%
function imf = emd(x,n);
load noissin;
x=noissin;
c = x(:)'; % copy of the input signal (as a row vector)
N = length(x);
%-------------------------------------------------------------------------
% loop to decompose the input signal into n successive IMFs
imf = []; % Matrix which will contain the successive IMF, and the residue
n=size(c);
for t=1:n % loop on successive IMFs
%-------------------------------------------------------------------------
% inner loop to find each imf
h = c; % at the beginning of the sifting process, h is the signal
SD = 1; % Standard deviation which will be used to stop the sifting process
while SD > 0.3 % while the standard deviation is higher than 0.3 (typical value)
% find local max/min points
d = diff(h); % approximate derivative
maxmin = []; % to store the optima (min and max without distinction so far)
for i=1:N-2
if d(i)==0 % we are on a zero
if sign(d(i-1))~=sign(d(i+1))% it is a maximum
maxmin = ;
end
elseif sign(d(i))~=sign(d(i+1)) % we are straddling a zero so
maxmin = ; % define zero as at i+1 (not i)
end
end
if size(maxmin,2) < 2 % then it is the residue
break
end
% divide maxmin into maxes and mins
if maxmin(1)>maxmin(2) % first one is a max not a min
maxes = maxmin(1:2:length(maxmin));
mins= maxmin(2:2:length(maxmin));
else % is the other way around
maxes = maxmin(2:2:length(maxmin));
mins= maxmin(1:2:length(maxmin));
end
% make endpoints both maxes and mins
maxes = ;
mins= ;
%-------------------------------------------------------------------------
% spline interpolate to get max and min envelopes; form imf
maxenv = spline(maxes,h(maxes),1:N);
minenv = spline(mins, h(mins),1:N);
m = (maxenv + minenv)/2; % mean of max and min enveloppes
prevh = h; % copy of the previous value of h before modifying it
h = h - m; % substract mean to h
% calculate standard deviation
eps = 0.0000001; % to avoid zero values
SD = sum ( ((prevh - h).^2) ./ (prevh.^2 + eps) );
end
imf = ; % store the extracted IMF in the matrix imf
% if size(maxmin,2)<2, then h is the residue
% stop criterion of the algo. if we reach the end before n
if size(maxmin,2) < 2
break
end
c = c - h; % substract the extracted IMF from the signal
end
return
{:{19}:}{:{19}:}没人帮忙吗 俺也不会，俺也想知道 一样不会，刚开始接触，工具箱怎么弄，还不明白呢 {:{19}:}{:{28}:}
页:
[1]