Wavelet plotting with imagesc

Question

Nikolas 2016-7-27

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/297404-wavelet-plotting-with-imagesc

回答： Nikolas 2016-7-27

Dear all, I am trying to plot the results of wavelet decomposition using imagesc and unfortunately this is not working properly.

The plot is perfect using surf, but the plot returned with this command is too heavy (and consequently slow) to manipulate (zoom in/out), so I need to do this with imagesc.

The code I am using is the following:

%Example 5s long signal
sr = 1000;
t = linspace(0,5,5*sr);
sig =  2*cos(2*pi*100*t).*(t<0.500)+3*cos(2*pi*300*t).* (t>0.500 & t <1)+randn(size(t));
WaveletName='cmor2-1';
fc = centfrq(WaveletName);
freqrange = [10 300];
scalerange = fc./(freqrange*(1/sr));
scales = scalerange(end):1:scalerange(1);
Coeffs = cwt(sig,scales,WaveletName);
F = scal2frq(scales,WaveletName,1/sr);
figure; 
subplot(1,2,1); 
surf(t,F,abs(Coeffs),'EdgeColor','none');  view(2); colorbar; title('Surf'); 
subplot(1,2,2); 
imagesc(t,F,abs(Coeffs)); axis xy; colorbar; title('Imagesc');