xbfj.m

基于hht的大地电磁信号资料处理MATLAB方法实现

function ii=xbfj(x,t,n,cy)
%对信号进行小波分解并对各系数序列进行FFT变化
%x为信号，T为对应时间，N为分解层数，CY为采样频率
figure(1);
subplot(2,1,1);
plot(t,x);
ylabel('signal');
        xlabel('T/s');
subplot(2,1,2);
[k,f]=fftp(x,1,cy);
       yMax = max(k);
        yMin = min(k);
        xMax = max(f);
        xMin = min(f);
    axis([xMin xMax yMin yMax]);
       ylabel('signal');
        xlabel('Frequency/Hz');
        
wname='db5';
[c,l] = wavedec(x,n,wname);
figure(2);
for i=1:n;
    d(i,:)=wrcoef('d',c,l,wname,i);
    subplot(n+1,1,i);
    plot(t,d(i,:));
    s1='d';
    s2=[s1 num2str(i)];
    ylabel(s2);
    
    if i==n;
        a(i,:)=wrcoef('a',c,l,wname,i);
        subplot(n+1,1,n+1);
        plot(t,a(i,:));
        s1='a';
        s2=[s1 num2str(i)];
        ylabel(s2);
        xlabel('T/s');
    end
end

figure(3);
for i=1:n;
    d(i,:)=wrcoef('d',c,l,wname,i);
    subplot(n+1,1,i);
 
    [k,f]=fftp(d(i,:),1,cy);
       yMax = max(k);
        yMin = min(k);
        xMax = max(f);
        xMin = min(f);
    axis([xMin xMax yMin yMax]);
    s1='d';
    s2=[s1 num2str(i)];
    ylabel(s2);
    
    if i==n;
        a(i,:)=wrcoef('a',c,l,wname,i);
        subplot(n+1,1,n+1);
        [k,f]=fftp(a(i,:),1,cy);
       yMax = max(k);
        yMin = min(k);
        xMax = max(f);
        xMin = min(f);
        s1='a';
        s2=[s1 num2str(i)];
        ylabel(s2);
        xlabel('Frequency/Hz');
    end
    end

end