Each of these transforms were coded in MATLAB and tested on.
change the 1st two lines with the tests info. m), the continuous wavelet (Morlet) transform (CWVT.m), and the pseudo-Wigner distribution (PWD.m). also further I have frequencies like 0.03,0.5,1.3 in my actual work. waves with frequencies of 150 and 200 Hz. The length of the block is equal to the sampling frequency.
#Sampling frequency of wavelet matlab code code
so the question is "what sampling rate should I select to see frequencies in range of. The CWT with the bump wavelet produces a time-frequency analysis very similar. The code uses Matlabs blockproc function to accomplish this with a specified step size in seconds. should I define my signal with different sampling rate like more resolution. as I see the freq are 0.5,0,0.9,1,2.7 due this code which are not close to what it must be. expected frequencies are 0.03,0.07,0.1 But the Output of this code shows frequency in range of0,10in the plot.
(2) Improve the threshold function, use improved algorithm for denoising, verify its validity and feasibility. I changed that bit but still I cant see the expected frequencies. cause the signal doesn't have enough information. The code in this article mainly completes the following work: (1) Exploring the influence of small-wavelength, decomposition layer, threshold rules, and threshold functions on denoising effects. test3: f=,N=300,Fs=10 the result is Inaccurate.with N=3000,Fs=100 the result is still inaccurate.also with N=30,Fs=1. Test2: f=,N=300,Fs=10 the result is very accurate.but i am wonder when I change the N=3000,Fs=100 the result is inaccurate.while I remained more information for my signal by N=3000,Fs=100 the last test show what i mean clearly. but with changing the N=3000,Fs=100 the result is fine and shows the desired frequencies. test1: f=,N=300,Fs=10 the result is not very accurate but it is bearable cause the information was not enough.
Still there is sth that confuse me about selecting the proper sampling rates.Here I run 3 tests to clarify what I mean.