1dBandpass¶
Usage: 1dBandpass [options] fbot ftop infile¶
* infile is an AFNI *.1D file; each column is processed
* fbot = lowest frequency in the passband, in Hz
[can be 0 if you want to do a lowpass filter only,]
but the mean and Nyquist freq are always removed ]
* ftop = highest frequency in the passband (must be > fbot)
[if ftop > Nyquist freq, then we have a highpass filter only]
* You cannot construct a 'notch' filter with this program!
* Output vectors appear on stdout; redirect as desired
* Program will fail if fbot and ftop are too close for comfort
* The actual FFT length used will be printed, and may be larger
than the input time series length for the sake of efficiency.
Options:¶
-dt dd = set time step to 'dd' sec [default = 1.0]
-ort f.1D = Also orthogonalize input to columns in f.1D
[only one '-ort' option is allowed]
-nodetrend = Skip the quadratic detrending of the input
-norm = Make output time series have L2 norm = 1
Example:¶
1deval -num 1000 -expr 'gran(0,1)' > r1000.1D
1dBandpass 0.025 0.20 r1000.1D > f1000.1D
1dfft f1000.1D - | 1dplot -del 0.000977 -stdin -plabel 'Filtered |FFT|'
Goal:¶
* Mostly to test the functions in thd_bandpass.c -- RWCox -- May 2009
++ Compile date = Oct 17 2024 {AFNI_24.3.03:linux_ubuntu_24_64}