%==========================================================================
%?小波變換里的延拓算法的實現
%?函數：extension
%?輸入：???x—待延拓的信號
%?????????exlength-延拓的擴展長度???????
%?????????type-選擇延拓的方式
%?輸出：???y—信號x的延拓結果
%?2012.9.28
%==========================================================================
function?[yexname]=extension（xexlengthtype）
%tyoe的0-4分別對應延拓類型：連續延拓、周期延拓、對稱延拓、補零延拓
????ex=[];
????ex=[ex?x];???
????len=length（x）;??????%需要處理的信號長度
????
????switch?type
??????case?0????????????%?連續延拓
???????????for?t=1:exlength
???????????????ex=[ex（:1）?ex?ex（:len）];
???????????end
???????????ex=ex‘;
???????????for?k=1:exlength
???????????????ex=[ex（:1）?ex?ex（:len）];
???????????end
???????????ex=ex‘;
???????????exname=‘連續延拓‘;

??????case?1????????????%?周期延拓
???????????for?t=1:exlength
???????????????ex=[ex（:len-t+1）?ex?ex（:t）];
???????????end
???????????ex=ex‘;
???????????for?t=1:exlength
???????????????ex=[ex（:len-t+1）?ex?ex（:t）];
???????????end
???????????ex=ex‘;??
???????????exname=‘周期延拓‘;

??????case?2????????????%?對稱延拓
???????????for?t=1:exlength
???????????????ex=[ex（:t）?ex?ex（:len-t+1）];
???????????end
???????????ex=ex‘;
???????????for?t=1:exlength
???????????????ex=[ex（:t）?ex?ex（:len-t+1）];
???????????end
???????????ex=ex‘;??
???????????exname=‘對稱延拓‘;
????
??????otherwise???????????%?補零延拓
???????????temp=zeros（lenexlength）;
???????????ex=[temp?ex?temp];
???????????ex=ex‘;
???????????temp=zeros（len+2*exlengthexlength）;
???????????ex=[temp?ex?temp];
???????????ex=ex‘;
???????????exname=‘補零延拓‘;
????end??
????y=ex;
end

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件???????1725??2012-10-09?12:58??實驗1?二維離散小波變換（Mallat快速算法）\extension.m

?????文件????????983??2012-09-29?13:22??實驗1?二維離散小波變換（Mallat快速算法）\filters.m

?????文件???????4315??2012-10-09?16:47??實驗1?二維離散小波變換（Mallat快速算法）\main.m

?????文件???????5497??2012-10-09?16:52??實驗1?二維離散小波變換（Mallat快速算法）\mallat.m

?????文件???????1329??2012-10-09?01:02??實驗1?二維離散小波變換（Mallat快速算法）\mallatDe.m

?????文件???????2128??2012-10-09?00:56??實驗1?二維離散小波變換（Mallat快速算法）\mallatRe.m

?????文件????1012702??2013-03-21?00:24??實驗1?二維離散小波變換（Mallat快速算法）\實驗1?二維離散小波變換（Mallat快速算法）.pdf

?????目錄??????????0??2013-03-21?00:25??實驗1?二維離散小波變換（Mallat快速算法）

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??????????????1028679????????????????????8