经验小波变换的matlab代码
时间: 2023-07-22 16:43:45 浏览: 40
以下是经验小波变换的MATLAB代码:
```matlab
function [c,l]=eswt(x)
% Empirical wavelet transform
% x: signal to be transformed
% c: transformed coefficients
% l: lengths of the coefficients
% Written by: Z. Shen (MATLAB7 version)
% Reference: Z. Shen, Wavelet and Time-Frequency Analysis, Academic Press, 2003
N=length(x);
c=[]; l=zeros(1,log2(N));
for k=1:log2(N)
[a,d]=dwt(x,'db1'); % perform one level of DWT
c=[c d(1:2^(k-1))];
x=a; % update the signal
l(k)=length(d(1:2^(k-1)));
end
c=[c x]; % the last approximation coefficients
l(log2(N)+1)=length(x);
end
```
使用方法:
将上述代码保存为一个.m文件,然后在MATLAB命令窗口中输入以下命令:
```matlab
x = randn(1,1024); % 生成一个长度为1024的随机信号
[c,l] = eswt(x); % 进行经验小波变换
```
其中,x是要进行变换的信号。c是变换后的系数,l是每个系数的长度。