Please help me!! Asking about Real-valued continuous wavelet transform and Complex-valued continuous wavelet transform

Hi Everyone!!

My name is Supatat, Now I am doing research about detecting aburpt transition of roll angular velocity of rail vehicle using continuous wavelet transform.

I have used MATLAB2014 and MATLAB2019 to perform continuous wavelet transform. The difference between 2014 and 2019 version is the wavelet coefficient. MATLAB2014 version returns real-valued wavelet coefficient while 2019 version returns complex-valued wavelet coefficient.

This is the analyzed roll angular velocity signal

This is the continuous wavelet transform result form MATLAB2014[using morlet wavelet 'morl']

This is the continuous wavelet transform result form MATLAB2019[using morlet wavelet 'amor']

Form the results above, For 2014 version, we can see that the maximum wavelet coefficient is located at low frequency area[around 1-2Hz]. However, for 2019 version, the maximum one is located at around 10~20Hz. And the order of coefficient are also different.

I don't understand why I got different results (because of the difference between 2 versions as I mentioned?)

Moreover, which result is correct? Could anyone please answer my all questions ?

Thank you very much in advance for your help