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reference:ft_globalmeanfield [2018/08/23 14:43] (current)
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 +Note that this reference documentation is identical to the help that is displayed in MATLAB when you type "help ft_globalmeanfield"​.
 +  <a href=/​reference/​ft_globalmeanfield><​font color=green>​FT_GLOBALMEANFIELD</​font></​a>​ calculates global mean field amplitude or power of input data
 +  Use as
 +    [gmf] = ft_globalmeanfield(cfg,​ data)
 +  The data should be organised in a structure as obtained from the
 +  <a href=/​reference/​ft_timelockanalysis><​font color=green>​FT_TIMELOCKANALYSIS</​font></​a>​ function. The configuration should be according to
 +  <a href=/​reference/​ft_preprocessing><​font color=green>​FT_PREPROCESSING</​font></​a>​ function. The configuration should be according to
 +    cfg.method ​   = string, determines whether the amplitude or power should be calculated (see below, default is '​amplitude',​ can be '​power'​)
 +    cfg.channel ​  = Nx1 cell-array with selection of channels (default = '​all'​),​
 +                             see <a href=/​reference/​ft_channelselection><​font color=green>​FT_CHANNELSELECTION</​font></​a>​ for details
 +  This function calculates the global mean field power, or amplitude,
 +  as described in:
 +  Lehmann D, Skrandies W. Reference-free identification of components of
 +  checkerboard-evoked multichannel potential fields. Electroencephalogr Clin
 +  Neurophysiol. 1980 Jun;​48(6):​609-21. PubMed PMID: 6155251.
 +  Please note that to calculate what is clasically referred to as Global
 +  Mean Field Power, cfg.method must be '​amplitude'​. The naming implies a
 +  squared measure but this is not the case.
 +  To facilitate data-handling and distributed computing you can use
 +    cfg.inputfile ​  ​= ​ ...
 +    cfg.outputfile ​ =  ...
 +  If you specify one of these (or both) the input data will be read from a *.mat
 +  file on disk and/or the output data will be written to a *.mat file. These mat
 +  files should contain only a single variable, corresponding with the
 +  input/​output structure.
 +  See also <a href=/​reference/​ft_timelockanalysis><​font color=green>​FT_TIMELOCKANALYSIS</​font></​a>​