[Eeglablist] Fixed FFT analysis window for coherence analysis

[Tatsuhide Oga]

Dear all, 

I am just wondering how I can change the length of 
FFT analysis window for computating coherence. 
And we know the resolution of frequency bins is
determined by the length of FFT analysis window.
Actually running "crossf" automatically determines it
depending on the length of epoch data. 
We are now analyzing a data with short length of
epoch (about 150 ms with sampling rate of 2048 Hz), 
and want to analyze with about 50 ms (around 128 time points) 
or 100 ms (128 time points) even without stepping. 
I would like to know how to fix the 
FFT analysis winodow and stepping window size 
within this short length under using crossf function.
Any infomation would be appreciated.

Oga