Correlation between mother wavelet and ECG signal

Hi all,

I am doing wavelet denoising for my ECG signal. In order to choose best mother wavelet for my signal, i have to correlate it first with my input signal.

How can i correlate a mother wavelet and ECG signal in Matlab? I can correlate two ECG signals, but not a mother wavelet and a ECG signal.

This due to the fact that i cannot get mother wavelet in an array. All i get is "db4" or "db8" as a character. How can i get a mother wavelet into an array and correlate with my signal?

[phani]

hi remo,

       I think you may use  some of the matlab functions like "morlet" to get the morlet mother wavelet and "mexh" for mecxican hat wavelet.

[remo]

Hi Mr.Phani,

Thank you for your time in answering my question.

Now i am able to get Morlet wavelet in matlab. But, wavelet of interest to me is Db4,5,6 . I cannot get these wavelets since there are no builtin functions just like for Morlet wavelet.

[ATHIRA]

use wavefun in matlab.we will get both wavelet and scaling function.Then change the size of the wavelet function to match with the signal and then find out correlation

Answer 1

[Wayne King]

The results for wavelet denoising should not be that heavily dependent on the choice of wavelet.

For EEG data, I would recommend starting with one of Daubechies' least asymmetric wavelets with at least 4 vanishing moments, 'sym4' for example.

[debojit sharma]

For time-frequency analysis, Can I use symlets wavelet family in CWT?

I mean if I use the in-built function of MatLab 'cwt' to find CWT coefficient of a signal as follows:

cfs=cwt(y,scales,'sym4','plot');

cfs=abs(cfs);

Is it valid to use symlet wavelet here for CWT? In earlier version of MatLab this was there.