It creates blocks of surrogate data with the same second order properties as the original time series dataset by transforming the original data into the frequency domain, randomizing the phases simultaneously across the time series and converting the data back into the time domain.
I appreciate your effort. But i have couple of doubts
1) You mentioned phases to be completely random but why did you use conjugate and flipud command after randomizing lower half. I tried without conj, flipud but the 2nd order moments are not preserved then u should be correct. Can you please delineate the reason
2) Reason for using same random phases across different series
3) what about first observation
It will be helpful if u reply me fast
Thanks in advance
This is not the correct way of randomizing phase.
Thanks for the suggestion. Very usefull