I've a couple of questions about the use of the CWT MATLAB function (cwt(,)) applied to a real time signal x. The questions are as follows:
1) If I'm filtering a signal (x) with a cut off frequency supposed to be equal to 5 Hz, by plotting cwt(x) I should see bright spots (high magntude) just for frequency lower than 5Hz rigth?
2) How can I reduce the frequency range on the ylabel? I mean, once I input the signal and the sampling frequency of the signal, a certain range of frequencies is automatically given on ylabel. Can I modify it? How? For example, in case of point 1) I have a signal that, once filtered, has significant component around 5Hz, therefore I'm not interested in information up to 200 Hz.
3) In the case I would like to plot the difference between the cw coefficients obtained from to signals, resepctively x1 and x2, how can I do? Which is the best way to do it? I know how to compute the coefficients and plot the two distinct cases but I don't know how to plot the module of the coefficient difference. Which is the function I should use?
Thank you very much in advance.