HHT精华讨论

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FÉ î˜fork=1:size(E)bjp(k)=sum(E(k,:))*1/fs;%fs:Ç7‘‡;endfigureplot(bjp);xlabel('‘‡/Hz');ylabel('E');Ԃ($*c&á÷\ÿfs=1000;t=1/fs:1/fs:1;y1=2*sin(40*pi*t);y2=5*sin(80*pi*t);y=[y1,y2];%á÷;úe„þˆ—Ùô(ôùžEá÷†@å'¶‚Ueîcćà-¹E1ùžEá÷/ˆ}„aò¿(hhspectrum—†1þöB†¹E1¹E1ú,óÕformӜ_*}20HZØL40HZ1 ›î˜†ÁDþT1`êñ(Ù*ÕÕ¡ (rilling„hhspectrumnspab:functionh1=nspab(data,nyy,minw,maxw,dt)%ThefunctionNSPABgeneratesasmoothedHHTspectrumofdata(n,k)%intime-frequencyspace,where%nspecifiesthelengthoftimeseries,and%kisthenumberofIMFcomponents.%Thefrequency-axisrangeisprefixed.%Negativefrequencysignisreversed.%%MATLABLibraryfunctionHILBERTisusedtocalculatetheHilberttransform.%%Example,[h,xs,w]=nspab(lod78_p',200,0,0.12,1,3224).%%FunctionsCONTOURorIMGcanbeusedtoviewthespectrum,%forexamplecontour(xs,w,h)orimg(xs,w,h).%%Callingsequence-%[h,xs,w]=nspab(data,nyy,minw,maxw,t0,t1)%%Input-%data-2-Dmatrixdata(n,k)ofIMFcomponents%nyy-thefrequencyresolution%minw-theminimumfrequency%maxw-themaximumfrequency%t0-thestarttime%t1-theendtime%Output-%h-2-DmatrixoftheHHTspectrum,where%the1stdimensionspecifiesthenumberoffrequencies,%the2nddimensionspecifiesthenumberoftimevalues%xs-vectorthatspecifiesthetime-axisvalues%w-vectorthatspecifiesthefrequency-axisvalues%Z.Shen(JHU)July2,1995Initial%-----Getdimensions(numberoftimepointsandcomponents)[npt,knb]=size(data);%-----Gettimeinterval%-----ApplyHilbertTransformdata=hilbert(data);a=abs(data);omg=abs(diff(unwrap(angle(data))))/(2*pi*dt);%-----Smoothamplitudeandfrequencyfiltr=fir1(8,.1);fori=1:knba(:,i)=filtfilt(filtr,1,a(:,i));omg(:,i)=filtfilt(filtr,1,omg(:,i));end%-----Limitfrequencyandamplitudefori=1:knbfori1=1:npt-1ifomg(i1,i)=maxw,omg(i1,i)=maxw;a(i1,i)=0;elseifomg(i1,i)=minw,omg(i1,i)=minw;a(i1,i)=0;elseendendendclearfiltrdata%va=var(omg(200:1200))%-----Getlocalfrequencydw=maxw-minw;wmx=maxw;wmn=minw;%-----Constructtheplotingmatrixclearp;h1=zeros(npt-1,nyy+1);p=round(nyy*(omg-wmn)/dw)+1;forj1=1:npt-1fori1=1:knbii1=p(j1,i1);h1(j1,ii1)=h1(j1,ii1)+a(j1,i1);endend%-----Do3-pointto1-pointaveraging[nx,ny]=size(h1);%n1=fix(nx/3);%h=zeros(n1,ny);%fori1=1:n1%h(i1,:)=(h1(3*i1,:)+h1(3*i1-1,:)+h1(3*i1-2,:));%end%clearh1;%-----Do3-pointssmoothinginx-directionfltr=1./3*ones(3,1);forj1=1:nyh1(:,j1)=filtfilt(fltr,1,h1(:,j1));endclearfltr;%-----Definetheresults%w=linspace(wmn,wmx,ny-1)';%xs=linspace(t0,t1,nx)';h1=flipud(rot90(h1));h1=h1(1:ny-1,:);íformB¹E1ö@(/¡ („/ébïlÖ@—Óœcn„Ÿà/“e„”/(†toimage„Óœ/(†hhspectrum„ÓœbÙµ'¶ïå»Õ¹E1„Óœ/Œhcn„clear;fs=1000;%fs:Ç7‘‡;N=1000;%Ç7¹pt=1/fs:1/fs:1;y1=2*sin(60*pi*t);y2=5*sin(90*pi*t);y=[y1;y2;zeros(size(y1))];%IMFÆ%%%%%%%%%%%%%B¹E1[A,fa,tt]=hhspectrum(y);[E,tt1]=toimage(A,fa,tt,length(tt));E=flipud(E);fork=1:size(E,1)bjp(k)=sum(E(k,:))*1/fs;endf=(0:N-3)/N*(fs/2);plot(f,bjp);xlabel('‘‡/Hz');ylabel('E');%ŒtTH î†`„ à¹}–Hy=[y1;y2;zeros(size(y1))];%IMFÆÙåãh„+I/ÀH`}Ï¡ \EMDêÌ IMFØ 1/E=flipud(E);Ùå„\(/ÀHT*c&ýp,«1/*IMF@åy=[y1;y2;zeros(size(y1))]1/*IMFÆS6Gš†‹Yýp:0 ps(†toimage—0„ÓœM/c„Hilbert1
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Hilbert¹E1ŒFTØb„E‘1ٗú„Hilbert¹E1ŒFTØb„E‘1:ÀH ÙH'„:+b0•ê*EM/c„žEEb Â÷‚loadshujufs=5120;N=4096;a1=a(1:N,1);a2=abs(fft(a1))*2/N;f=fs*(0:N/2-1)/N;n=length(f);subplot(211)plot(f,a2(1:n))xlabel('‘‡/Hz');ylabel('E');title('FT„E‘þ')imf=emd(a1);[A,fa,tt]=hhspectrum(imf);[E,tt1]=toimage(A,fa,tt,length(tt));fork=1:size(E,1)bjp(k)=sum(E(k,:))*1/fs;endf=(0:N-3)/N*(fs/2);subplot(212)plot(f,bjp);xlabel('‘‡/Hz');ylabel('E');title('Hilbert¹E1')TEMDã„IMFýόŸá÷výÏ/øI„@å¹E1ýÏýŒFFT„ýÏøÔ¹E1ýÏêýôÐ*á÷X(ýÏøùŽvք'¹E1/ùIMFÖÜ¿àdƒ—0„1ýρ'Ž«Ö܄á÷ýÏFFT1ŒŸá÷„ýÏ/øI„@åÎýτ'²”å/¹E1ýÏ'ŽFFT„ýÏ‚œ/*âÖ¹E1ŒFFT„Ý”å/‘‡ù”„ýϹE1'ŽFFT3
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