wscalogram and subplots

Hi.

I'm trying to make a subplot containing a scalogram, original signal and a spectrogram.

The problem is that MATLAB ignores the scalogram and just doesn't show it. The original signal obtained in the top using wscalogram should not be showed, only the scalogram and another original signal made by some other commands. So how to do that?

subplot(3,1,1); the plot of the original signal

subplot(3,1,2); wscalogram('image',c,'scales',scales,'ydata',signal,'xdata', t)

subplot(3,1,3); the plot of the spectrogram

So I want the ydata to be gone but the xdata should still be shown on the x-axis for the scalogram, and when I delete ydata, xdata has no influence.

I hope you can help!

-Trine

Answer 1

[Wayne King]

Hi Trine, Call wscalogram() with the first input just ' ' and return an output, which you can plot as an image. For example:

   wname = 'mexh';
   scales = (1:128);
   load cuspamax
   signal = cuspamax;
   coefs = cwt(signal,scales,wname);
   SCimg = wscalogram('',coefs,'scales',scales,'ydata',signal);
   subplot(311)
   plot(signal); ylabel('Amplitude');
   subplot(312)
   imagesc(1:length(signal),scales,SCimg);
   axis xy;
   ylabel('Scales'); xlabel('Time'); title('Wavelet Scalogram');
   subplot(313)
   %plot spectrogram here

[Zhao Lu]

very helpful !