Bandpass,Lpfilt - Bandpass dataset
Bandpass <in.H flo=0. fhi=0.5/dt nplo=6 nphi=6 phase=0 > out.H
Lpfilt <in.H f3db= order=6 > out.H
low and high cutoff frequencies; flo for lowcut filter (no default); fhi=[0.5/dt] for highcut; gain at flo and fhi is: -6db for zero-phase filter -3db for minimum-phase filter. flo and f3db are equivalent
number of poles for low and high cutoffs; filter roll-off rate is proportional to number of poles (order,nplo are equvilant)
[0]: for zero-phase; =1 for minimum-phase
Butterworth bandpass filter.
Bandpass <in.H in=stdin out=stdout flo=0. fhi=0.5/dt nplo=6 nphi=6 phase=0 > out.H
Technical reference: Oppenheim, A.V., and Schafer, R.W., 1975, Digital signal processing, Prentice-Hall Inc.
seis/filter