FieldTrip

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

  FT_SOURCEINTERPOLATE interpolates the source reconstructed activity
  or a statistical distribution onto the voxels or vertices of an
  anatomical description of the brain.  Both the functional and the
  anatomical data can either describe a 3-dimensional volume, a
  triangulated description of the cortical sheet or an arbitrary cloud
  of points.
 
  The following scenarios are possible:
 
  -The functional data is defined on a low resolution 2-dimensional triangulated
   mesh, the vertices being a subset of the high resolution 2-dimensional
   triangulated anatomical mesh. This allows for mesh based interpolation. The
   algorithm currently implemented is so-called 'smudging' as it is also
   applied by the MNE-suite software.
 
  -Both the functional and the anatomical data are defined on an irregular
   point cloud (can be a 2D triangulated mesh).
 
  -The functional data is defined on an irregular point cloud (can be a 2D
   triangulated mesh), and the anatomical data is a volumetric image.
 
  -The functional data is defined on a 3D regular grid of source positions
   and the anatomical data is defined on an irregular point cloud (can be a
   2D triangulated mesh).
 
  -The functional data is defined on a 3D regular grid of source positions
   and the anatomical data is a volumetric image.
 
  The functional and anatomical data should be expressed in the same
  coordinate sytem, i.e. either both in CTF coordinates (NAS/LPA/RPA)
  or both in SPM coordinates (AC/PC).
 
  The output data will contain a description of the functional data
  at the locations at which the anatomical data are defined. For
  example, if the anatomical data was volumetric, the output data is
  a volume-structure, containing the resliced source and the anatomical
  volume that can be plotted together, using FT_SOURCEPLOT or
  FT_SLICEINTERP, or that can be written to file using FT_SOURCEWRITE.
 
  Use as
    [interp] = ft_sourceinterpolate(cfg, source, anatomy)
    [interp] = ft_sourceinterpolate(cfg, stat, anatomy)
  where
    source  is the output of FT_SOURCEANALYSIS
    stat    is the output of FT_SOURCESTATISTICS
    anatomy is the output of FT_READ_MRI or one of the FT_VOLUMExxx functions, 
            or a cortical sheet that was read with FT_READ_HEADSHAPE. 
  and cfg is a structure with any of the following fields
    cfg.parameter     = string (or cell-array) of the parameter(s) to be interpolated
    cfg.interpmethod  = 'linear', 'cubic', 'nearest' or 'spline' when
                        interpolating two 3D volumes onto each other
                        (default = 'linear')
    cfg.interpmethod  = 'nearest', 'sphere_avg' or 'smudge' when
                        interpolating a point cloud onto a 3D volume, a
                        3D volume onto a point cloud, or a point cloud
                        with another point cloud (default = 'nearest')
    cfg.downsample    = integer number (default = 1, i.e. no downsampling)
 
  To facilitate data-handling and distributed computing with the peer-to-peer
  module, this function has the following options:
    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 FT_SOURCEANALYSIS, FT_SOURCESTATISTICS, FT_READ_MRI,
  FT_READ_HEADSHAPE