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

  function [FM, xf] = ft_preproc_online_filter_apply(FM, x)
 
  Passes signal x (channels times samples) through the filter,
  returns updated filter model (delay states) and filtered signal.
 
  See also FT_PREPROC_ONLINE_FILTER_INIT