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1、實(shí)用標(biāo)準(zhǔn)文案http://www.chinavib.com/forum-viewthread-tid-9141-extra-page%3D1-page-1.html（個(gè)人收集關(guān)于小波分析的matlab程序）小波濾波器構(gòu)造和消噪程序1小波譜分析mallat算法經(jīng)典程序7小波包變換分析信號的MATLAB程序9利用小波變換實(shí)現(xiàn)對電能質(zhì)量檢測的算法實(shí)現(xiàn)15基于小波變換的圖象去噪Normalshrink算法17小波濾波器構(gòu)造和消噪程序1．重構(gòu)%mallet_wavelet.m%此函數(shù)用于研究Mallet算法及濾波器設(shè)計(jì)%
2、此函數(shù)僅用于消噪a=pi/8;%角度賦初值b=pi/8;%低通重構(gòu)FIR濾波器h0(n)沖激響應(yīng)賦值h0=cos(a)*cos(b);h1=sin(a)*cos(b);h2=-sin(a)*sin(b);h3=cos(a)*sin(b);low_construct=[h0,h1,h2,h3];L_fre=4;%濾波器長度low_decompose=low_construct(end:-1:1);%確定h0(-n)，低通分解濾波器fori_high=1:L_fre;%確定h1(n)=(-1)^n,高通重建濾波器i
3、f(mod(i_high,2)==0);coefficient=-1;精彩文檔實(shí)用標(biāo)準(zhǔn)文案elsecoefficient=1;endhigh_construct(1,i_high)=low_decompose(1,i_high)*coefficient;endhigh_decompose=high_construct(end:-1:1);%高通分解濾波器h1(-n)L_signal=100;%信號長度n=1:L_signal;%信號賦值f=10;t=0.001;y=10*cos(2*pi*50*n*t).*ex
4、p(-20*n*t);figure(1);plot(y);title('原信號');check1=sum(high_decompose);%h0(n)性質(zhì)校驗(yàn)check2=sum(low_decompose);check3=norm(high_decompose);check4=norm(low_decompose);l_fre=conv(y,low_decompose);%卷積l_fre_down=dyaddown(l_fre);%抽取,得低頻細(xì)節(jié)h_fre=conv(y,high_decompose);h_
5、fre_down=dyaddown(h_fre);%信號高頻細(xì)節(jié)精彩文檔實(shí)用標(biāo)準(zhǔn)文案figure(2);subplot(2,1,1)plot(l_fre_down);title('小波分解的低頻系數(shù)');subplot(2,1,2);plot(h_fre_down);title('小波分解的高頻系數(shù)');l_fre_pull=dyadup(l_fre_down);%0差值h_fre_pull=dyadup(h_fre_down);l_fre_denoise=conv(low_construct,l_fre_pu
6、ll);h_fre_denoise=conv(high_construct,h_fre_pull);l_fre_keep=wkeep(l_fre_denoise,L_signal);%取結(jié)果的中心部分,消除卷積影響h_fre_keep=wkeep(h_fre_denoise,L_signal);sig_denoise=l_fre_keep+h_fre_keep;%信號重構(gòu)compare=sig_denoise-y;%與原信號比較figure(3);subplot(3,1,1)plot(y);ylabel('y'
7、);%原信號subplot(3,1,2);plot(sig_denoise);ylabel('sig_denoise');%重構(gòu)信號精彩文檔實(shí)用標(biāo)準(zhǔn)文案subplot(3,1,3);plot(compare);ylabel('compare');%原信號與消噪后信號的比較1．消噪、%此函數(shù)用于研究Mallet算法及濾波器設(shè)計(jì)%此函數(shù)用于消噪處理%角度賦值%此處賦值使濾波器系數(shù)恰為db9%分解的高頻系數(shù)采用db9較好,即它的消失矩較大%分解的有用信號小波高頻系數(shù)基本趨于零%對于噪聲信號高頻分解系數(shù)很大，便于閾值
8、消噪處理[l,h]=wfilters('db10','d');low_construct=l;L_fre=20;%濾波器長度low_decompose=low_construct(end:-1:1);%確定h0(-n)，低通分解濾波器fori_high=1:L_fre;精彩文檔實(shí)用標(biāo)準(zhǔn)文案%確定h1(n)=(-1)^n,高通重建濾波器if(mod(i_high,2)==0);coeff
