Forward computations of the EEG/MEG leadfields

FieldTrip has a consistent set of low-level functions for forward computations of the EEG potential or MEG field. The spatial distribution of a known source in a volume conductor is called a leadfield.

The forward module comprises a complete toolbox of high-quality forward methods, i.e. it contains all functions to set up the volume conduction models of the head and to compute the leadfields. Using the high-level FieldTrip functions and the inverse module, these can be used for reconstructing the sources given real experimental MEG and EEG data.

The objective of supplying these low-level functions as a seperate module/toolbox are to

  1. facilitate the reuse of these functions in other open-source projects (e.g. EEGLAB, SPM)
  2. facilitate the implementation and support for new inverse methods, esp. for external users/contributors
  3. facilitate the implementation of advanced features

The low-level functions for source estimation/reconstruction are contained in the forward and inverse toolboxes, which are released together with FieldTrip. If you are interested in using them seperately from the FieldTrip main functions, you can also download them separately here. For reference: in the past the forward and inverse modules were combined in a single “forwinv” toolbox.

Please note that if you are an end-user interested in analyzing experimental EEG/MEG data, you will probably will want to use the high-level FieldTrip functions. The functions such as ft_preprocessing, ft_timelockanalysis and ft_sourceanalysis provide a user-friendly interface that take care of all relevant analysis steps and the data bookkeeping.

Module layout

The forward module contains functions with a user interface that will be easily understood by experimenced programmers and methods developers and can be considered medium-level functions. They have a clear and consistent programming interface (API) which hides the specific details particular volume conduction models and that allows software developers to write forward methods without having to worry about integrating it with the inverse methods worry about data handling. The low-level functions on which the functions in the forward module depend are located in a private subdirectory which is not accessible from the MATLAB command line.

The forward module is complemented by an inverse module that contains the implementation of various high-quality inverse source estimation algorithms, such as dipole fitting, beamforming and linear estimation using the minimum-norm approach.

Instead of implementing all forward methods completely from scratch, the FieldTrip forward module makes use of some high quality implementations that have been provided by the original method developers. Some of these contributions consist of MATLAB code, some contain MEX files and some are implemented using an external command-line executable that is called from the command-line. All of these external implementations are fully wrapped in the FieldTrip forward module and do not require specific expertise on behalf of the end-user.

forward EEG and MEG leadfield computations with FIeldTrip

Supported methods for forward computations of the potential or field

The following forward methods are implemented for computing the electric potential (EEG):

  • single sphere
  • multiple concentric spheres with up to 4 shells
  • boundary element model (BEM)
  • leadfield interpolation using a precomputed grid
  • all forward models supported by the Neuromag meg-calc toolbox


The following forward methods are implemented for computing the magnetic field (MEG):

  • single sphere (Cuffin and Cohen, 1977)
  • multiple spheres with one sphere per channel (Huang et al, 1999)
  • realistic single-shell model based on leadfield expansion (Nolte, 2003)
  • leadfield interpolation using a precomputed grid
  • all forward models supported by the Neuromag meg-calc toolbox


Definition of the function-calls (API)

Volume conduction models of the head are represented as a MATLAB structure, which content depends on the model details. In the subsequent documentation the volume conduction model structure is referred to as vol. The electrodes in case of EEG, or magnetometers or gradiometers in case of MEG, are described as a MATLAB structure. In teh subsequent documentation this is referred to as elec for electrodes, grad for magmetometers and/or gradiometers, or sens to represent either electrodes or gradiometers.

Using the FieldTrip fileio module one can read in volume conduction models and the definition of the sensor array (electrodes or gradiometers) from file by using the ft_read_vol and/or ft_read_sens functions: 

[vol]  = ft_read_vol(filename)
[sens] = ft_read_sens(filename)

This assumes that the volume conduction model was created in external software (e.g. CTF, Neuromag, or ASA) and that the sensor description is stored in an external acquisition-specific file format.

Alternative to reading the volume conduction model from an external file, you can of course also generate a volume conduction model based on a geometrical description of the head. For example, you can fit a single or multiple spheres to a set of points that describes the head surface. FieldTrip provides a separate function for the constructing of a head model for each of the EEG/MEG computational forward methods: 

[vol] = ft_headmodel_asa(filename, ...)
[vol] = ft_headmodel_bem_cp(geom, ...)
[vol] = ft_headmodel_concentricspheres(geom, ...)
[vol] = ft_headmodel_dipoli(geom, ...)
[vol] = ft_headmodel_halfspace(location, orientation, ...)
[vol] = ft_headmodel_infinite(...)
[vol] = ft_headmodel_localspheres(geom, grad, ...)
[vol] = ft_headmodel_openmeeg(geom, ...)
[vol] = ft_headmodel_singleshell(geom, sens, ...)
[vol] = ft_headmodel_singlesphere(pnt, ...)

Most of these functions take a geometrical description of the head, skull and/or brain surface as input. These geometrical descriptions of the shape of the head can for example be derived from an anatomical MRI, from a CT scan, or from a Polhemus measurement of the outside of the scalp. In most cases the geometrical model consists of a Nx3 matrix with surface points, which is sometimes accompanied with a description of the triangles that form the surface. The processing of the anatomical data such as MRIs to construct a geometrical model is not part of the forward module and is described elsewhere.

Detailed information for each of the functions that creates a head model can be found in the respective reference documentation: ft_headmodel_asa, ft_headmodel_bemcp, ft_headmodel_concentricspheres, ft_headmodel_dipoli, ft_headmodel_halfspace, ft_headmodel_infinite, ft_headmodel_localspheres, ft_headmodel_openmeeg, ft_headmodel_singleshell, ft_headmodel_singlesphere.

If desired the volume conduction model and the sensor array can be spatially transformed using a 4×4 homogenous transformation matrix. E.g. the electrodes can be translated and rotated to align them with head coordinate system, or they can be translated and rotated to switch to another coordinate system. 

[vol]  = ft_transform_vol(transform, vol)
[sens] = ft_transform_sens(transform, sens)

The reason for using the ft_transform_sens and ft_transform_vol functions is that they allow you to transform any sensor type (EEG and/or MEG) and any volume conduction model without you having to manipulate the elements within the sens or vol structure.

Up to here the head model only depends on the geometrical description of the volume conductor and is independent of the data, with exception of the MEG localspheres model. The consequence is that the head model can be used for multiple experimental sessions, multiple electrode or gradiometer placements, or different selections of channels for a single session. The head model, i.e. the vol structure, can be saved to disk and re-used in an analysis on the next day.

Following the initial set-up of the head model, but prior to the actual forward computations, the ft_prepare_vol_sens function should be called to link the head model and the sensors and make a data dependent forward model (consisting of the vol and sens). 

[vol, sens] = ft_prepare_vol_sens(vol, sens, ...)

The ft_prepare_vol_sens function does a variety of things, depending on the peculiarities of the sensors and head model. It can be used for channel selection, which sometimes involves both the sensors and volume conduction model (e.g. in case of a localspheres MEG model). It will project EEG electrodes (which are described as a Nx3 set of points) onto the scalp surface. It will provide an interpolation of the BEM potential (which is usually computed at the vertices) onto the electrodes. In general the ft_prepare_vol_sens function tries to carry out as many preparations as possible, so that subsequently the leadfields can be computed as efficiently as possible.

Finally the subsequent computation of the EEG potential or MEG field distribution is done with the ft_compute_leadfield function: 

[lf] = ft_compute_leadfield(pos, sens, vol, ...)

Most functions have additional optional input arguments that are specified as key-value pairs.

Boundary element method (BEM) implementations

FieldTrip relies on external contributed software for the low-level computations of the BEM system matrix. The external software is included in the standard FieldTrip release in the external directory.

fieldtrip/external/openmeeg

The MATLAB interface to the OpenMEEG implementation is kindly provided by Maureen Clerc, Alexandre Gramfort, and co-workers.

The OpenMEEG software is developed within the Athena project-team at INRIA Sophia-Antipolis and was initiated in 2006 by the Odyssee Project Team (INRIA/ENPC/ENS Ulm). OpenMEEG solves forward problems related to Magneto- and Electro-encephalography (MEG and EEG) using the symmetric Boundary Element Method, providing excellent accuracy.

fieldtrip/external/bemcp

The bemcp implementation is kindly provided by Christophe Phillips.

fieldtrip/external/dipoli

The dipoli implementation is kindly provided by Thom Oostendorp.

Recent changes to the forward code

2012-05-22 15:15  vlalit

	* [r5796] private/channelposition.m: automatically synchronized identical files to revision
	  5795

2012-05-15 09:14  crimic

	* [r5778] ft_senstype.m: bugfix - added a check on the input type of ft_senstype, in case
	  the second argument contains spectral data, then no sensor definition is attached

2012-05-14 10:09  crimic

	* [r5776] ft_headmodel_bem_dipoli.m: enhancement - after dipoli head matrix generation, flip
	  the boundary normals outwards again, to maintain a consistent convention

2012-05-13 12:20  roboos

	* [r5775] ft_compute_leadfield.m: enhancement - small change to the metufem forward model as
	  requested by Zeynep

2012-05-09 08:11  roboos

	* [r5753] ft_senstype.m: bugfix - also detect combined planar ctf151 as ctf151, required to
	  solve bug 1288. Updated the test scrtipr. Also made another small change in ft_senstype
	  for the isheader case: there was a piece of code that could not be not reached.

2012-05-06 16:22  crimic

	* [r5742] ft_compute_leadfield.m: bugfix - corrected the assignment of leadfields in case of
	  re-referenced batch fields

2012-05-06 11:49  roboos

	* [r5741] ft_compute_leadfield.m: enhancement - disabled the warning on the units, it is not
	  clear what the user should do with it

2012-05-02 13:59  crimic

	* [r5727] ft_fetch_headshape.m: bugfix - introduced the correct handling of headshape inputs

2012-05-01 20:35  roboos

	* [r5722] private/ft_hastoolbox.m: automatically synchronized identical files to revision
	  5721

2012-04-30 11:26  crimic

	* [r5714] ft_compute_leadfield.m: bugfix - this addresses bug #70, lately reopened due to
	  regression test failing

2012-04-21 06:04  eelspa

	* [r5688] private/fixname.m: automatically synchronized identical files to revision 5687

2012-04-21 05:59  eelspa

	* [r5686] private/fixname.m: automatically synchronized identical files to revision 5685

2012-04-19 13:56  jansch

	* [r5669] private/warp_apply.m: automatically synchronized identical files to revision 5668

2012-04-19 09:37  eelspa

	* [r5662] private/fixname.m: automatically synchronized identical files to revision 5661

2012-04-18 14:10  eelspa

	* [r5652] private/fixname.m: automatically synchronized identical files to revision 5651

2012-04-15 10:56  roboos

	* [r5625] ft_headmodel_concentricspheres.m, ft_headmodel_singlesphere.m: enhancement - small
	  change in unit handling

2012-04-15 10:46  roboos

	* [r5624] ft_headmodel_concentricspheres.m, ft_headmodel_localspheres.m,
	  ft_headmodel_singlesphere.m: enhancement - allow the input geometry as vol.bnd.pn, bnd.pnt
	  or pnt (see bug 1414). Deal with geometrical units in a consistent manner.

2012-04-13 14:52  crimic

	* [r5613] ft_compute_leadfield.m: enhancement - added flag to manage non-adaptive behavior
	  in openmeeg_dsm

2012-04-04 10:50  roboos

	* [r5589] ft_convert_units.m, ft_voltype.m: enhancement - hardened the ft_convert_units
	  function, see http://bugzilla.fcdonders.nl/show_bug.cgi?id=1405#c4

2012-04-04 10:29  roboos

	* [r5587] ft_senstype.m: bugfix - an MRI structure can have a header, which confused the
	  header detection. Fixed the specific problem and added a test script. See
	  http://bugzilla.fcdonders.nl/show_bug.cgi?id=1405

2012-03-30 14:31  roboos

	* [r5573] ft_senstype.m: bugfix - only check for neuralynx channel in hase isheader

2012-03-30 09:33  roboos

	* [r5567] ft_senstype.m: automatically synchronized identical files to revision 5566

2012-03-28 18:56  roboos

	* [r5557] private/ft_hastoolbox.m: automatically synchronized identical files to revision
	  5556

2012-03-27 09:46  eelspa

	* [r5540] private/ft_getopt.mexw64, private/lmoutr.mexw64, private/meg_leadfield1.mexw64,
	  private/plgndr.mexw64, private/ptriproj.mexw64, private/routlm.mexw64,
	  private/solid_angle.mexw64: automatically synchronized identical files to revision 5539

2012-03-22 09:32  roboos

	* [r5512] private/ft_getopt.mexw32, private/lmoutr.mexw32, private/meg_leadfield1.mexw32,
	  private/plgndr.mexw32, private/ptriproj.mexw32, private/routlm.mexw32,
	  private/solid_angle.mexw32: automatically synchronized identical files to revision 5511

2012-03-21 14:01  crimic

	* [r5504] ft_compute_leadfield.m: bugfix - this relates to bug #1368, normalization is now
	  possible also for batch leadfields

2012-03-20 13:37  crimic

	* [r5494] ft_headmodel_fem_simbio.m: enhancement - modified simbio headmodel function to
	  allow for tetrahedrons meshes

2012-03-15 11:49  crimic

	* [r5468] ft_prepare_vol_sens.m: bugfix - changed 'coilpos' name into 'elecpos' in the EEG
	  part

2012-03-13 18:11  crimic

	* [r5451] ft_headmodel_singlesphere.m: enhancement - added unit input to single sphere
	  headmodel

2012-03-10 21:25  roboos

	* [r5434] private/fixname.m: automatically synchronized identical files to revision 5433

2012-03-10 15:42  roboos

	* [r5432] private/ft_hastoolbox.m, private/warning_once.m: automatically synchronized
	  identical files to revision 5431

2012-03-10 15:41  roboos

	* [r5431] private/fixname.m: enhancement - replaced the multiple occuring subfunction
	  fixname by a single one, see http://bugzilla.fcdonders.nl/show_bug.cgi?id=1273#c2

2012-03-07 11:47  crimic

	* [r5408] ft_headmodel_bemcp.m: bugfix - cfg.hdmfile is now managed in the higher level
	  ft_prepare_heamdole function

2012-03-07 11:40  crimic

	* [r5407] ft_fetch_headshape.m, ft_headmodel_bem_dipoli.m, ft_headmodel_bem_openmeeg.m,
	  private/ft_fetch_headshape.m: restructuring - added ft_fetch_headmodel to retrieve the
	  correct input fot headmodel functions

2012-03-07 10:26  crimic

	* [r5406] ft_headmodel_bem_asa.m: enhancement - minor correction to the function's input

2012-03-05 14:01  roboos

	* [r5389] private/warning_once.m: automatically synchronized identical files to revision
	  5388

2012-03-01 14:03  crimic

	* [r5365] ft_headmodel_infinite.m, private/eeg_infinite_monopole.m: enhancement - added
	  infinite monopole solution

2012-03-01 14:02  crimic

	* [r5364] private/ft_hastoolbox.m: automatically synchronized identical files to revision
	  5363

2012-03-01 13:53  crimic

	* [r5362] private/ft_fetch_headshape.m: enhancement - added routine to consistently load the
	  headshape within all headmodel functions

2012-02-29 23:44  crimic

	* [r5353] ft_compute_leadfield.m, ft_inside_vol.m, ft_prepare_vol_sens.m, ft_sourcedepth.m,
	  private/eeg_leadfieldb.m: bugfix - fixed bug #1029

2012-02-29 17:13  crimic

	* [r5346] ft_convert_units.m, ft_voltype.m: automatically synchronized identical files to
	  revision 5345

2012-02-29 16:08  crimic

	* [r5341] private/eeg_leadfieldb.m: bugfix - changed the name of the vol types and deleted
	  the obsolete 'avo' format
	  

2012-02-15 14:02  crimic

	* [r5288] ft_voltype.m: automatically synchronized identical files to revision 5287

2012-02-15 14:02  crimic

	* [r5287] private/eeg_slab_monopole.m, test/test_headmodel_bemcp_new_old.m: bugfix - updated
	  some recent changes

2012-02-15 10:24  crimic

	* [r5283] ft_convert_units.m: bugfix - this refers to bug 1309, fixed the elseif ladder to
	  convert the inputs

2012-02-10 09:36  jansch

	* [r5271] private/ft_datatype_sens.m, private/ft_hastoolbox.m: automatically synchronized
	  identical files to revision 5270

2012-02-08 13:19  roboos

	* [r5261] private/ft_hastoolbox.m: automatically synchronized identical files to revision
	  5260

2012-02-04 09:08  roboos

	* [r5235] private/ft_hastoolbox.m: automatically synchronized identical files to revision
	  5234

2012-02-03 09:02  jansch

	* [r5232] private/headcoordinates.m: automatically synchronized identical files to revision
	  5231

2012-02-01 12:57  crimic

	* [r5196] ft_compute_leadfield.m: bugfix - rank reduction applied to openmeeg lf too

2012-01-24 12:06  crimic

	* [r5168] private/eeg_slab_monopole.m: bugfix - changed a parameter in the mirror charges

2012-01-17 12:37  borreu

	* [r5144] ft_convert_units.m: bugfix - fixed bug1112 (problem in estimation of head size in
	  ft_convert_sens).

2012-01-11 07:53  roboos

	* [r5112] private/ft_hastoolbox.m: automatically synchronized identical files to revision
	  5111

2012-01-05 09:05  eelspa

	* [r5096] private/ft_getopt.mexa64, private/ft_getopt.mexglx, private/ft_getopt.mexmaci,
	  private/ft_getopt.mexmaci64, private/ft_getopt.mexw32, private/ft_getopt.mexw64,
	  private/lmoutr.mexa64, private/lmoutr.mexglx, private/lmoutr.mexmac,
	  private/lmoutr.mexmaci, private/lmoutr.mexmaci64, private/lmoutr.mexw32,
	  private/lmoutr.mexw64, private/meg_leadfield1.mexa64, private/meg_leadfield1.mexglx,
	  private/meg_leadfield1.mexmac, private/meg_leadfield1.mexmaci,
	  private/meg_leadfield1.mexmaci64, private/meg_leadfield1.mexw32,
	  private/meg_leadfield1.mexw64, private/plgndr.mexa64, private/plgndr.mexglx,
	  private/plgndr.mexmac, private/plgndr.mexmaci, private/plgndr.mexmaci64,
	  private/plgndr.mexw32, private/plgndr.mexw64, private/ptriproj.mexa64,
	  private/ptriproj.mexglx, private/ptriproj.mexmac, private/ptriproj.mexmaci,
	  private/ptriproj.mexmaci64, private/ptriproj.mexw32, private/ptriproj.mexw64,
	  private/routlm.mexa64, private/routlm.mexglx, private/routlm.mexmac,
	  private/routlm.mexmaci, private/routlm.mexmaci64, private/routlm.mexw32,
	  private/routlm.mexw64, private/solid_angle.mexa64, private/solid_angle.mexglx,
	  private/solid_angle.mexmac, private/solid_angle.mexmaci, private/solid_angle.mexmaci64,
	  private/solid_angle.mexw32, private/solid_angle.mexw64: setting svn:executable property on
	  all MEX files, properly this time I hope

2011-12-23 14:55  borreu

	* [r5082] private/ptriproj.mexw64, private/solid_angle.mexw64: automatically synchronized
	  identical files to revision 5081

2011-12-22 17:04  roboos

	* [r5079] private/ft_hastoolbox.m: automatically synchronized identical files to revision
	  5078

2011-12-22 17:04  roboos

	* [r5078] ft_senslabel.m, ft_senstype.m: enhancement - improved support for the 9-channel
	  small animal Yokogawa MEG system at UCL, see
	  http://bugzilla.fcdonders.nl/show_bug.cgi?id=1225

2011-12-22 13:40  borreu

	* [r5076] private/ft_getopt.m: automatically synchronized identical files to revision 5075

2011-12-22 08:58  roboos

	* [r5073] ft_senstype.m: automatically synchronized identical files to revision 5072

2011-12-21 13:58  roboos

	* [r5065] private/ft_getopt.m, private/ft_getopt.mexglx: automatically synchronized
	  identical files to revision 5064

2011-12-20 14:03  jansch

	* [r5058] private/ft_getopt.mexmaci, private/ft_getopt.mexmaci64: automatically synchronized
	  identical files to revision 5057

2011-12-20 13:48  eelspa

	* [r5056] private/ft_getopt.m, private/ft_getopt.mexa64, private/ft_getopt.mexw32,
	  private/ft_getopt.mexw64: automatically synchronized identical files to revision 5055

2011-12-14 10:47  roboos

	* [r5036] ft_apply_montage.m, private/ama2vol.m, private/undobalancing.m: automatically
	  synchronized identical files to revision 5035

2011-12-14 10:47  roboos

	* [r5035] ft_prepare_vol_sens.m: bugfix - use a consistent handling of the sparse
	  multiplication for claibrating data after reading and for computing channel leadfields
	  from the coils. See http://bugzilla.fcdonders.nl/show_bug.cgi?id=1169#c7

2011-12-09 15:33  roboos

	* [r4972] ft_convert_units.m, ft_estimate_units.m, private/cornerpoints.m: enhancement -
	  improved ft_determine_coordsys and underlying plotting functions to deal with mouse MRI,
	  the interpolation is now much faster (since more tight). Also added a "cornerpoints"
	  helper function (also used in ft_convert_units), improved documentation here and there.
	  Added range (replacement for the stats version) to utilities/private.

2011-12-09 14:30  tilsan

	* [r4968] ft_senstype.m: automatically synchronized identical files to revision 4967

2011-12-05 08:59  jansch

	* [r4934] private/ft_hastoolbox.m: automatically synchronized identical files to revision
	  4933

2011-12-04 18:39  hundan

	* [r4931] ft_compute_leadfield.m, test/test_headmodel_fns.m: Update routine to compute the
	  lead field matrices.

2011-12-01 21:29  roboos

	* [r4924] private/ft_datatype_sens.m: automatically synchronized identical files to revision
	  4923

2011-12-01 17:03  roboos

	* [r4921] private/ft_hastoolbox.m: automatically synchronized identical files to revision
	  4920

2011-11-27 22:35  crimic

	* [r4863] ft_headmodel_fdm_fns.m, private/leadfield_fns.m, test/test_headmodel_fns.m: bugfix
	  - corrected segmentation file writing options and made fns i/o files compatible with each
	  other

2011-11-20 20:36  crimic

	* [r4780] ft_headmodel_fdm_fns.m: enhancement - latest modifications to FNS toolbox

2011-11-17 23:28  crimic

	* [r4771] ft_headmodel_bem_openmeeg.m, test/test_headmodel_openmeeg_new_old.m: bugfix -
	  added some options' defaults

2011-11-17 22:53  crimic

	* [r4770] ft_headmodel_concentricspheres.m, test/test_headmodel_concentricspheres.m,
	  test/test_headmodel_concentricspheres_new_old.m: bugfix - fixed concentric spheres fwd
	  solution

2011-11-17 22:32  crimic

	* [r4769] ft_headmodel_bemcp.m: bugfix - fixed iput defaults

2011-11-17 13:56  crimic

	* [r4766] ft_headmodel_bem_dipoli.m, test/test_headmodel_dipoli.m,
	  test/test_headmodel_dipoli_new_old.m: bugfix - fixed some defaults

2011-11-17 12:32  crimic

	* [r4764] private/leadfield_simbio.m: bugfix - added the format of the input vista file to
	  be written on disk

2011-11-16 17:50  crimic

	* [r4759] ft_voltype.m: enhancement - added some definitions to the datatype_headmodel and
	  voltype functions

2011-11-16 14:07  tilsan

	* [r4751] private/ft_hastoolbox.m: automatically synchronized identical files to revision
	  4750

2011-11-16 13:15  crimic

	* [r4749] ft_headmodel_fem_simbio.m, private/leadfield_simbio.m,
	  test/test_headmodel_simbio.m: bugfix - refers to bug #1048 changed the name of
	  tetra/hexahedral mesh

2011-11-13 14:01  roboos

	* [r4730] private/ft_hastoolbox.m: automatically synchronized identical files to revision
	  4729

2011-11-11 09:45  crimic

	* [r4722] compat/dipoli.m: bugfix - fix units cconversion

2011-11-10 18:20  crimic

	* [r4721] test/test_headmodel_singlesphere.m: bugfix - adapted new forward model functions
	  with mri input to singlesphere

2011-11-10 15:50  roboos

	* [r4716] private/channelposition.m: automatically synchronized identical files to revision
	  4715

2011-11-10 15:31  jorhor

	* [r4712] ft_headmodel_bem_openmeeg.m, ft_headmodel_fdm_fns.m, ft_headmodel_fem_simbio.m:
	  bugfix-#1065- remove ~ from functions as dummy variable, replaced by tmp

2011-11-10 10:45  crimic

	* [r4705] private/ft_hastoolbox.m: enhancement - synch of all hastoolbox functions

2011-11-10 09:23  borreu

	* [r4702] compat/dipoli.m: bugfix #1113 - replaced CVS $Log$ messages with SVN $Id$.

2011-11-08 15:33  crimic

	* [r4698] ft_headmodel_bem_openmeeg.m, test/test_headmodel_openmeeg.m: bugfix - fixed
	  openmeeg test file

2011-11-08 15:27  crimic

	* [r4697] test/test_headmodel_bemcp.m: bugfix - changed chanpos in test file, now working

2011-11-07 16:37  crimic

	* [r4691] test/test_headmodel_fns.m: bugfix - fixed a return carriage typo

2011-11-07 15:50  crimic

	* [r4687] test/test_headmodel_fns.m: enhancement - automatized the pipeline for FNS

2011-11-04 15:49  roboos

	* [r4680] test/test_headmodel_asa.m, test/test_headmodel_bemcp.m,
	  test/test_headmodel_concentricspheres.m, test/test_headmodel_dipoli.m,
	  test/test_headmodel_openmeeg.m, test/test_headmodel_singlesphere.m: bugfix - replaced
	  sens.pnt by sens.chanpos and sens.elecpos

2011-11-04 15:46  roboos

	* [r4679] test/test_headmodel_concentricspheres.m: bugfix - replaced sens.pnt with
	  sens.chanpos

2011-11-04 10:00  crimic

	* [r4677] private/surface_nesting.m: bugfix - fixed naive bug from copy and paste

2011-11-04 08:56  roboos

	* [r4676] ft_headmodel_concentricspheres.m: bugfix - the function tried to access vol.bnd
	  which did not exist. Instead it should determine the number of boundaries by numel(geom)

2011-11-03 21:22  roboos

	* [r4671] private/ft_datatype_sens.m: automatically synchronized identical files to revision
	  4670

2011-11-03 21:22  roboos

	* [r4670] ft_convert_units.m: added a test script for bug 1112, extended the
	  test_ft_datatype_sens script, added some comments

2011-11-02 10:33  crimic

	* [r4650] ft_headmodel_bem_dipoli.m, ft_headmodel_bem_openmeeg.m, ft_headmodel_bemcp.m,
	  ft_headmodel_concentricspheres.m: enhancement - upgrade of the boundaries nesting
	  management

2011-11-02 10:27  crimic

	* [r4649] private/surface_nesting.m: enahncement - added private nesting function

2011-10-31 21:29  roboos

	* [r4645] private/ft_hastoolbox.m: automatically synchronized identical files to revision
	  4644

Related documentation

The literature references to the implemented methods are given here.

Frequently asked questions about forward and inverse modeling:

Example material for forward and inverse modeling:

Tutorial material for forward and inverse modeling:

development/forward.txt · Last modified: 2011/08/18 11:19 by eelke

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