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fScan Reference Manual, Chapter 2 (CmdLineOptions:Expr): Bandpass
usage: -expr bandpass flag slowfreq fastfreq scalefact
The BANDPASS function will filter out both low and high frequency signals. Usually, frequencies slower than SLOWFREQ and faster than FASTFREQ will be filtered out. For convenience, frequencies are typically expressed as wavelengths in seconds, so a slow frequency cut-off would be something like 30-60s and a high frequency something like 2-3s, depending on what frequency wavelengths you want to preserve. If SLOWFREQ is faster than FASTFREQ, then BANDPASS acts as a notch filter to remove frequencies between SLOWFREQ and FASTFREQ (instead of frequencies outside that range).
SCALEFACT is a scaling factor; FFT output intensity values will be divided by SCALEFACT. Default SCALEFACT is 1000.
The FLAG argument can be used to select filtering options.
FLAG:
Example:
See Also:
fScan Home,
fScan Manual,
CmdLineOptions,
Expression Command,
Manual Help