vbfit

From VoxBoWiki

vbfit fits three parameters to describe a 1/f function fit to the power spectrum of your data. Here's the help text:

VoxBo vbfit
usage:
  vbfit <TR> <totalReps> [-r <refFunc>] <ps#1> [<ps#2> ...] [-o <output>]

        <TR>:  time of repetition (unit: ms)
 <totalReps>:  total # of image based on which power spectrum will be drawn
   <refFunc>:  reference function file (optional)
      <ps#1>:  power spectrum file #1 (ps#2, ps#3 ... are optional)
    <output>:  filename where fitting parameters will be saved
               (optional, default is no file generation)