資源簡(jiǎn)介
用于求取小波包變換后小波系數(shù)的熵值,對(duì)初學(xué)者很有幫助
代碼片段和文件信息
%求小波包的信息熵
%ECG為信號(hào)源,n為分解的層數(shù),wpname為小波名字,我常用的是db3haardb4.?
function?y=waveletentropy(ECGnwpname)?
ECG=imread(‘Empreinte.bmp‘);
n=3;
wpname=‘bior3.5‘;
wpt1=wpdec2(ECGnwpname);?%對(duì)數(shù)據(jù)進(jìn)行小波包分解?
for?i=1:2*n?%wpcoef(wpt1[ni-1])是求第n層第i個(gè)節(jié)點(diǎn)的系數(shù)?
disp(‘每個(gè)節(jié)點(diǎn)的能量E(i)‘);?
E(i)=norm(wpcoef(wpt1[ni-1])2)*norm(wpcoef(wpt1[ni-1])2)?
%求第i個(gè)節(jié)點(diǎn)的范數(shù)平方,其實(shí)也就是平方和?
end?
disp(‘小波包分解總能量E_total‘);?
E_total=sum(E)?%求總能量?
disp(‘以下是每個(gè)節(jié)點(diǎn)的概率P‘);?
for?i=1:2*n?
p(i)=?E(i)/E_total?%求每個(gè)節(jié)點(diǎn)的概率?
end?
%以下計(jì)算小波熵,即-sum(pj*lnpj),?
disp(‘小波熵的值S_wt‘);?
for?i=1:2*n?
m(i)=p(i)*log(p(i));?
end?
S_wt=sum(m)*(-1)?
disp(‘小波包分解圖形‘);?
subplot(131);?
text(1010‘原始圖象‘)?;?
plot(ECG);?
subplot(132);?
text(10200‘概率分布圖象‘);?
plot(p);?
subplot(133);?
plot(E);?
?屬性????????????大小?????日期????時(shí)間???名稱
-----------?---------??----------?-----??----
?????文件????????843??2009-03-16?21:05??wavelet\小波.txt
?????文件?????120054??2007-07-24?09:47??wavelet\Empreinte.bmp
?????文件????????899??2011-04-15?14:55??wavelet\waveletentropy.m
????..A.SH.??????8704??2011-04-15?19:02??wavelet\Thumbs.db
?????目錄??????????0??2011-04-15?10:45??wavelet
-----------?---------??----------?-----??----
???????????????130500????????????????????5
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