Hi,
I'm trying to band pass filter using 3dFourier twice.
My block is 20s long and my TR=2s, so I figure I should keep everything between :
1/40s (being conservative) to 1/4s (nyquist)
so I do:
3dFourier -lowpass 0.25 -prefix 06_lp mydata+orig
3dFourier -highpass 0.025 -prefix 06_bp 06_lp+orig
looking at 06_lp, it's all 0's. But the high pass filtered version of 06_lp (06_bp) is not all 0's. This doesn't make sense. Am I doing something wrong?
thanks,
George