Note that this reference documentation is identical to the help that is displayed in MATLAB when you type “help ft_sourcegrandaverage”.
FT_SOURCEGRANDAVERAGE averages source reconstructions over either multiple subjects or conditions. It computes the average and variance for all known source parameters. The output can be used in FT_SOURCESTATISTICS with the method 'parametric'. Alternatively, it can construct an average for multiple input source reconstructions in two conditions after randomly reassigning the input data over the two conditions. The output then can be used in FT_SOURCESTATISTICS with the method 'randomization' or 'randcluster'. The input source structures should be spatially alligned to each other and should have the same positions for the source grid. Use as [grandavg] = ft_sourcegrandaverage(cfg, source1, source2, ...) where the source structures are obtained from FT_SOURCEANALYSIS or from FT_VOLUMENORMALISE, and the configuration can contain the following fields: cfg.parameter = string, describing the functional data to be processed, e.g. 'pow', 'nai' or 'coh' cfg.keepindividual = 'no' or 'yes' 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. For this particular function, the input data should be structured as a single cell array. See also FT_SOURCEANALYSIS, FT_VOLUMENORMALISE, FT_SOURCESTATISTICS