7.1.2. 1dBandpassΒΆ

Link to classic view

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 = Dec 16 2015

Table Of Contents

This Page