Note that this reference documentation is identical to the help that is displayed in MATLAB when you type “help fieldtrip2ctf”.

  FIELDTRIP2CTF saves a FieldTrip data structures to a corresponding CTF file. The
  file to which the data is exported depends on the input data structure that you
  provide.
 
  Use as
    fieldtrip2ctf(filename, data, ...)
  where "filename" is a string, "data" is a FieldTrip data structure, and
  additional options can be specified as key-value pairs.
 
  The FieldTrip "montage" structure (see FT_APPLY_MONTAGE and the cfg.montage
  option in FT_PREPROCESSING) can be exported to a CTF "Virtual Channels" file.
 
  At this moment the support for other FieldTrip structures and CTF fileformats is
  still limited, but this function serves as a placeholder for future improvements.
 
  See also FT_VOLUMEWRITE, FT_SOURCEWRITE, FT_WRITE_DATA