Note that this reference documentation is identical to the help that is displayed in MATLAB when you type “help ft_preproc_detrend”.

  FT_PREPROC_DETREND removes mean and linear trend from the
  data using using a General Linear Modeling approach.
 
  Use as
    [dat] = ft_preproc_detrend(dat, begin, end)
  where
    dat        = data matrix (Nchans X Ntime)
    begsample  = index of the begin sample for the trend estimate
    endsample  = index of the end sample for the trend estimate
 
  If no begin and end sample are specified for the trend estimate, it
  will be estimated on the complete data.
 
  See also FT_PREPROC_BASELINECORRECT, FT_PREPROC_POLYREMOVAL