BEM (Boundary Element Method) model definition. More...

#include <fwd_bem_model.h>

Public Types
typedef std::unique_ptr< FwdBemModel >	UPtr
typedef void(*	linFieldIntFunc) (const Eigen::Vector3f &dest, const Eigen::Vector3f &dir, MNELIB::MNETriangle &tri, Eigen::Vector3d &res)
	Function pointer type for linear field coefficient integration methods.

Public Member Functions
	FwdBemModel ()
	Constructs an empty BEM model.
virtual	~FwdBemModel ()
	Destroys the BEM model.
void	fwd_bem_free_solution ()
	Release the potential solution matrix and associated workspace.
MNELIB::MNESurface *	fwd_bem_find_surface (int kind)
	Find a surface of the given kind in this BEM model.
int	fwd_bem_load_solution (const QString &name, int bem_method)
	Load a pre-computed BEM solution from a FIFF file.
int	fwd_bem_set_head_mri_t (const FIFFLIB::FiffCoordTrans &t)
	Set the Head-to-MRI coordinate transform for this BEM model.
int	fwd_bem_linear_collocation_solution ()
	Compute the linear-collocation BEM solution for this model.
int	fwd_bem_constant_collocation_solution ()
	Compute the constant-collocation BEM solution for this model.
int	fwd_bem_compute_solution (int bem_method)
	Compute the BEM solution matrix using the specified method.
int	fwd_bem_load_recompute_solution (const QString &name, int bem_method, int force_recompute)
	Load a BEM solution from file, recomputing if necessary.
int	fwd_bem_specify_els (FwdCoilSet *els)
	Precompute the electrode-specific BEM solution.
void	fwd_bem_pot_grad_calc (const Eigen::Vector3f &rd, const Eigen::Vector3f &Q, FwdCoilSet *els, int all_surfs, Eigen::Ref< Eigen::VectorXf > xgrad, Eigen::Ref< Eigen::VectorXf > ygrad, Eigen::Ref< Eigen::VectorXf > zgrad)
	Compute the gradient of BEM potentials with respect to dipole position (constant collocation).
void	fwd_bem_lin_pot_calc (const Eigen::Vector3f &rd, const Eigen::Vector3f &Q, FwdCoilSet *els, int all_surfs, Eigen::Ref< Eigen::VectorXf > pot)
	Compute BEM potentials at electrodes using linear collocation.
void	fwd_bem_lin_pot_grad_calc (const Eigen::Vector3f &rd, const Eigen::Vector3f &Q, FwdCoilSet *els, int all_surfs, Eigen::Ref< Eigen::VectorXf > xgrad, Eigen::Ref< Eigen::VectorXf > ygrad, Eigen::Ref< Eigen::VectorXf > zgrad)
	Compute the gradient of BEM potentials with respect to dipole position (linear collocation).
void	fwd_bem_pot_calc (const Eigen::Vector3f &rd, const Eigen::Vector3f &Q, FwdCoilSet *els, int all_surfs, Eigen::Ref< Eigen::VectorXf > pot)
	Compute BEM potentials at electrodes using constant collocation.
Eigen::MatrixXf	fwd_bem_field_coeff (FwdCoilSet *coils)
	Assemble the constant-collocation magnetic field coefficient matrix.
Eigen::MatrixXf	fwd_bem_lin_field_coeff (FwdCoilSet *coils, int method)
	Assemble the linear-collocation magnetic field coefficient matrix.
int	fwd_bem_specify_coils (FwdCoilSet *coils)
	Precompute the coil-specific BEM solution for MEG.
void	fwd_bem_lin_field_calc (const Eigen::Vector3f &rd, const Eigen::Vector3f &Q, FwdCoilSet &coils, Eigen::Ref< Eigen::VectorXf > B)
	Compute BEM magnetic fields at coils using linear collocation.
void	fwd_bem_field_calc (const Eigen::Vector3f &rd, const Eigen::Vector3f &Q, FwdCoilSet &coils, Eigen::Ref< Eigen::VectorXf > B)
	Compute BEM magnetic fields at coils using constant collocation.
void	fwd_bem_field_grad_calc (const Eigen::Vector3f &rd, const Eigen::Vector3f &Q, FwdCoilSet &coils, Eigen::Ref< Eigen::VectorXf > xgrad, Eigen::Ref< Eigen::VectorXf > ygrad, Eigen::Ref< Eigen::VectorXf > zgrad)
	Compute the gradient of BEM magnetic fields with respect to dipole position (constant collocation).
void	fwd_bem_lin_field_grad_calc (const Eigen::Vector3f &rd, const Eigen::Vector3f &Q, FwdCoilSet &coils, Eigen::Ref< Eigen::VectorXf > xgrad, Eigen::Ref< Eigen::VectorXf > ygrad, Eigen::Ref< Eigen::VectorXf > zgrad)
	Compute the gradient of BEM magnetic fields with respect to dipole position (linear collocation).
int	compute_forward_meg (std::vector< std::unique_ptr< MNELIB::MNESourceSpace > > &spaces, FwdCoilSet coils, FwdCoilSet comp_coils, MNELIB::MNECTFCompDataSet *comp_data, bool fixed_ori, const Eigen::Vector3f &r0, bool use_threads, FIFFLIB::FiffNamedMatrix &resp, FIFFLIB::FiffNamedMatrix &resp_grad, bool bDoGRad)
	Compute the MEG forward solution for one or more source spaces.
int	compute_forward_eeg (std::vector< std::unique_ptr< MNELIB::MNESourceSpace > > &spaces, FwdCoilSet els, bool fixed_ori, FwdEegSphereModel eeg_model, bool use_threads, FIFFLIB::FiffNamedMatrix &resp, FIFFLIB::FiffNamedMatrix &resp_grad, bool bDoGrad)
	Compute the EEG forward solution for one or more source spaces.

Static Public Member Functions
static QString	fwd_bem_make_bem_sol_name (const QString &name)
	Build a standard BEM solution file name from a model name.
static const QString &	fwd_bem_explain_surface (int kind)
	Return a human-readable label for a BEM surface kind.
static const QString &	fwd_bem_explain_method (int method)
	Return a human-readable label for a BEM method.
static int	get_int (FIFFLIB::FiffStream::SPtr &stream, const FIFFLIB::FiffDirNode::SPtr &node, int what, int *res)
	Read an integer tag from a FIFF node.
static FwdBemModel::UPtr	fwd_bem_load_surfaces (const QString &name, const std::vector< int > &kinds)
	Load BEM surfaces of specified kinds from a FIFF file.
static FwdBemModel::UPtr	fwd_bem_load_homog_surface (const QString &name)
	Load a single-layer (homogeneous) BEM model from a FIFF file.
static FwdBemModel::UPtr	fwd_bem_load_three_layer_surfaces (const QString &name)
	Load a three-layer BEM model (scalp, outer skull, inner skull) from a FIFF file.
static std::unique_ptr< MNELIB::MNESurface >	make_guesses (MNELIB::MNESurface *guess_surf, float guessrad, const Eigen::Vector3f &guess_r0, float grid, float exclude, float mindist)
	Generate a set of dipole guess locations inside a boundary surface.
static double	calc_beta (const Eigen::Vector3d &rk, const Eigen::Vector3d &rk1)
	Compute the beta angle used in the linear collocation integration.
static void	lin_pot_coeff (const Eigen::Vector3f &from, MNELIB::MNETriangle &to, Eigen::Vector3d &omega)
	Compute the linear potential coefficients for one source-destination pair.
static void	correct_auto_elements (MNELIB::MNESurface &surf, Eigen::MatrixXf &mat)
	Correct the auto (self-coupling) elements of the linear collocation matrix.
static Eigen::MatrixXf	fwd_bem_lin_pot_coeff (const std::vector< MNELIB::MNESurface * > &surfs)
	Assemble the full linear-collocation potential coefficient matrix.
static Eigen::MatrixXf	fwd_bem_multi_solution (Eigen::MatrixXf &solids, const Eigen::MatrixXf *gamma, int nsurf, const Eigen::VectorXi &ntri)
	Compute the multi-surface BEM solution from solid-angle coefficients.
static Eigen::MatrixXf	fwd_bem_homog_solution (Eigen::MatrixXf &solids, int ntri)
	Compute the homogeneous (single-layer) BEM solution.
static void	fwd_bem_ip_modify_solution (Eigen::MatrixXf &solution, Eigen::MatrixXf &ip_solution, float ip_mult, int nsurf, const Eigen::VectorXi &ntri)
	Modify the BEM solution with the isolated-problem (IP) approach.
static int	fwd_bem_check_solids (const Eigen::MatrixXf &angles, int ntri1, int ntri2, float desired)
	Verify that solid-angle sums match the expected value.
static Eigen::MatrixXf	fwd_bem_solid_angles (const std::vector< MNELIB::MNESurface * > &surfs)
	Compute the solid-angle matrix for all BEM surfaces.
static float	fwd_bem_inf_field (const Eigen::Vector3f &rd, const Eigen::Vector3f &Q, const Eigen::Vector3f &rp, const Eigen::Vector3f &dir)
	Compute the infinite-medium magnetic field at a single point.
static float	fwd_bem_inf_pot (const Eigen::Vector3f &rd, const Eigen::Vector3f &Q, const Eigen::Vector3f &rp)
	Compute the infinite-medium electric potential at a single point.
static int	fwd_bem_pot_els (const Eigen::Vector3f &rd, const Eigen::Vector3f &Q, FwdCoilSet &els, Eigen::Ref< Eigen::VectorXf > pot, void *client)
	Callback: compute BEM potentials at electrodes for a dipole.
static int	fwd_bem_pot_grad_els (const Eigen::Vector3f &rd, const Eigen::Vector3f &Q, FwdCoilSet &els, Eigen::Ref< Eigen::VectorXf > pot, Eigen::Ref< Eigen::VectorXf > xgrad, Eigen::Ref< Eigen::VectorXf > ygrad, Eigen::Ref< Eigen::VectorXf > zgrad, void *client)
	Callback: compute BEM potentials and position gradients at electrodes.
static void	calc_f (const Eigen::Vector3d &xx, const Eigen::Vector3d &yy, Eigen::Vector3d &f0, Eigen::Vector3d &fx, Eigen::Vector3d &fy)
	Compute the f0, fx, fy integration helper values from corner coordinates.
static void	calc_magic (double u, double z, double A, double B, Eigen::Vector3d &beta, double &D)
	Compute the "magic" beta and D factors for the Urankar field integration.
static void	field_integrals (const Eigen::Vector3f &from, MNELIB::MNETriangle &to, double &I1p, Eigen::Vector2d &T, Eigen::Vector2d &S1, Eigen::Vector2d &S2, Eigen::Vector3d &f0, Eigen::Vector3d &fx, Eigen::Vector3d &fy)
	Compute the geometry integrals for the magnetic field from a triangle.
static double	one_field_coeff (const Eigen::Vector3f &dest, const Eigen::Vector3f &normal, MNELIB::MNETriangle &tri)
	Compute the constant-collocation magnetic field coefficient for one triangle.
static double	calc_gamma (const Eigen::Vector3d &rk, const Eigen::Vector3d &rk1)
	Compute the gamma angle for the linear field integration (Ferguson).
static void	fwd_bem_one_lin_field_coeff_ferg (const Eigen::Vector3f &dest, const Eigen::Vector3f &dir, MNELIB::MNETriangle &tri, Eigen::Vector3d &res)
	Compute linear field coefficients using the Ferguson method.
static void	fwd_bem_one_lin_field_coeff_uran (const Eigen::Vector3f &dest, const Eigen::Vector3f &dir, MNELIB::MNETriangle &tri, Eigen::Vector3d &res)
	Compute linear field coefficients using the Urankar method.
static void	fwd_bem_one_lin_field_coeff_simple (const Eigen::Vector3f &dest, const Eigen::Vector3f &normal, MNELIB::MNETriangle &source, Eigen::Vector3d &res)
	Compute linear field coefficients using the simple (direct) method.
static float	fwd_bem_inf_field_der (const Eigen::Vector3f &rd, const Eigen::Vector3f &Q, const Eigen::Vector3f &rp, const Eigen::Vector3f &dir, const Eigen::Vector3f &comp)
	Compute the derivative of the infinite-medium magnetic field with respect to dipole position.
static float	fwd_bem_inf_pot_der (const Eigen::Vector3f &rd, const Eigen::Vector3f &Q, const Eigen::Vector3f &rp, const Eigen::Vector3f &comp)
	Compute the derivative of the infinite-medium electric potential with respect to dipole position.
static int	fwd_bem_field (const Eigen::Vector3f &rd, const Eigen::Vector3f &Q, FwdCoilSet &coils, Eigen::Ref< Eigen::VectorXf > B, void *client)
	Callback: compute BEM magnetic fields at coils for a dipole.
static int	fwd_bem_field_grad (const Eigen::Vector3f &rd, const Eigen::Vector3f &Q, FwdCoilSet &coils, Eigen::Ref< Eigen::VectorXf > Bval, Eigen::Ref< Eigen::VectorXf > xgrad, Eigen::Ref< Eigen::VectorXf > ygrad, Eigen::Ref< Eigen::VectorXf > zgrad, void *client)
	Callback: compute BEM magnetic fields and position gradients at coils.
static void	meg_eeg_fwd_one_source_space (FwdThreadArg *arg)
	Thread worker: compute the forward solution for one source space.
static int	fwd_sphere_field (const Eigen::Vector3f &rd, const Eigen::Vector3f &Q, FwdCoilSet &coils, Eigen::Ref< Eigen::VectorXf > Bval, void *client)
	Callback: compute the spherical-model magnetic field at coils.
static int	fwd_sphere_field_vec (const Eigen::Vector3f &rd, FwdCoilSet &coils, Eigen::Ref< Eigen::MatrixXf > Bval, void *client)
	Callback: compute the spherical-model vector magnetic field at coils.
static int	fwd_sphere_field_grad (const Eigen::Vector3f &rd, const Eigen::Vector3f &Q, FwdCoilSet &coils, Eigen::Ref< Eigen::VectorXf > Bval, Eigen::Ref< Eigen::VectorXf > xgrad, Eigen::Ref< Eigen::VectorXf > ygrad, Eigen::Ref< Eigen::VectorXf > zgrad, void *client)
	Callback: compute the spherical-model magnetic field and its position gradient at coils.
static int	fwd_mag_dipole_field (const Eigen::Vector3f &rm, const Eigen::Vector3f &M, FwdCoilSet &coils, Eigen::Ref< Eigen::VectorXf > Bval, void *client)
	Callback: compute the magnetic field of a magnetic dipole at coils.
static int	fwd_mag_dipole_field_vec (const Eigen::Vector3f &rm, FwdCoilSet &coils, Eigen::Ref< Eigen::MatrixXf > Bval, void *client)
	Callback: compute the vector magnetic field of a magnetic dipole at coils.

Public Attributes
QString	surf_name
std::vector< std::shared_ptr< MNELIB::MNESurface > >	surfs
Eigen::VectorXi	ntri
Eigen::VectorXi	np
int	nsurf
Eigen::VectorXf	sigma
Eigen::MatrixXf	gamma
Eigen::VectorXf	source_mult
Eigen::VectorXf	field_mult
int	bem_method
QString	sol_name
Eigen::MatrixXf	solution
Eigen::VectorXf	v0
int	nsol
FIFFLIB::FiffCoordTrans	head_mri_t
float	ip_approach_limit
bool	use_ip_approach

Static Public Attributes
static constexpr double	MAG_FACTOR = 1e-7

Detailed Description

BEM (Boundary Element Method) model definition.

Holds the BEM model surfaces, conductivity parameters, and potential solution matrix used in MEG/EEG forward computations. Surfaces are stored from outermost to innermost and owned by this object.

Refactored from the MNE-C fwdBemModel / fwdBemModelRec struct (fwd_types.h). Raw C-style arrays replaced with Eigen types; surface ownership managed through std::unique_ptr.

Definition at line 128 of file fwd_bem_model.h.

Member Typedef Documentation

◆ linFieldIntFunc

typedef void(* FWDLIB::FwdBemModel::linFieldIntFunc) (const Eigen::Vector3f &dest, const Eigen::Vector3f &dir, MNELIB::MNETriangle &tri, Eigen::Vector3d &res)

Function pointer type for linear field coefficient integration methods.

Definition at line 721 of file fwd_bem_model.h.

◆ UPtr

typedef std::unique_ptr<FwdBemModel> FWDLIB::FwdBemModel::UPtr

Unique pointer type for FwdBemModel.

Definition at line 131 of file fwd_bem_model.h.

Constructor & Destructor Documentation

◆ FwdBemModel()

FwdBemModel::FwdBemModel ( )

explicit

Constructs an empty BEM model.

All Eigen containers are left at size zero; scalar members are set to safe defaults (nsurf = 0, nsol = 0, bem_method = FWD_BEM_UNKNOWN).

Definition at line 184 of file fwd_bem_model.cpp.

◆ ~FwdBemModel()

FwdBemModel::~FwdBemModel ( )

virtual

Destroys the BEM model.

FsSurface ownership is released automatically via std::unique_ptr. The solution matrix is freed by fwd_bem_free_solution().

Definition at line 196 of file fwd_bem_model.cpp.

Member Function Documentation

◆ calc_beta()

double FwdBemModel::calc_beta	(	const Eigen::Vector3d &	rk,
		const Eigen::Vector3d &	rk1 )

static

Compute the beta angle used in the linear collocation integration.

Parameters

[in]	rk	Position vector of vertex k.
[in]	rk1	Position vector of vertex k+1.

Returns: The beta angle value.

Definition at line 538 of file fwd_bem_model.cpp.

◆ calc_f()

void FwdBemModel::calc_f	(	const Eigen::Vector3d &	xx,
		const Eigen::Vector3d &	yy,
		Eigen::Vector3d &	f0,
		Eigen::Vector3d &	fx,
		Eigen::Vector3d &	fy )

static

Compute the f0, fx, fy integration helper values from corner coordinates.

Parameters

[in]	xx	Corner x-coordinates.
[in]	yy	Corner y-coordinates.
[out]	f0	Integral f0.
[out]	fx	Integral fx.
[out]	fy	Integral fy.

Definition at line 1539 of file fwd_bem_model.cpp.

◆ calc_gamma()

double FwdBemModel::calc_gamma	(	const Eigen::Vector3d &	rk,
		const Eigen::Vector3d &	rk1 )

static

Compute the gamma angle for the linear field integration (Ferguson).

Parameters

[in]	rk	Position vector of vertex k.
[in]	rk1	Position vector of vertex k+1.

Returns: The gamma angle value.

Definition at line 1783 of file fwd_bem_model.cpp.

◆ calc_magic()

void FwdBemModel::calc_magic	(	double	u,
		double	z,
		double	A,
		double	B,
		Eigen::Vector3d &	beta,
		double &	D )

static

Compute the "magic" beta and D factors for the Urankar field integration.

Parameters

[in]	u	Coordinate u.
[in]	z	Coordinate z.
[in]	A	Parameter A.
[in]	B	Parameter B.
[out]	beta	Output beta factor.
[out]	D	Output D factor.

Definition at line 1563 of file fwd_bem_model.cpp.

◆ compute_forward_eeg()

int FwdBemModel::compute_forward_eeg	(	std::vector< std::unique_ptr< MNELIB::MNESourceSpace > > &	spaces,
		FwdCoilSet *	els,
		bool	fixed_ori,
		FwdEegSphereModel *	eeg_model,
		bool	use_threads,
		FIFFLIB::FiffNamedMatrix &	resp,
		FIFFLIB::FiffNamedMatrix &	resp_grad,
		bool	bDoGrad )

Compute the EEG forward solution for one or more source spaces.

Parameters

[in]	spaces	Source spaces.
[in]	els	Electrode locations.
[in]	fixed_ori	If true, use fixed-orientation dipoles.
[in]	eeg_model	Sphere model definition.
[in]	use_threads	If true, parallelize across source spaces.
[out]	resp	Forward solution matrix.
[out]	resp_grad	Gradient forward solution matrix.
[in]	bDoGrad	If true, also compute the gradient solution.

Returns: OK on success, FAIL on error.

Definition at line 2815 of file fwd_bem_model.cpp.

◆ compute_forward_meg()

int FwdBemModel::compute_forward_meg	(	std::vector< std::unique_ptr< MNELIB::MNESourceSpace > > &	spaces,
		FwdCoilSet *	coils,
		FwdCoilSet *	comp_coils,
		MNELIB::MNECTFCompDataSet *	comp_data,
		bool	fixed_ori,
		const Eigen::Vector3f &	r0,
		bool	use_threads,
		FIFFLIB::FiffNamedMatrix &	resp,
		FIFFLIB::FiffNamedMatrix &	resp_grad,
		bool	bDoGRad )

Compute the MEG forward solution for one or more source spaces.

Parameters

[in]	spaces	Source spaces.
[in]	coils	MEG coil set.
[in]	comp_coils	Compensator coil set (may be nullptr).
[in]	comp_data	CTF compensation data (may be nullptr).
[in]	fixed_ori	If true, use fixed-orientation dipoles.
[in]	r0	Sphere model origin.
[in]	use_threads	If true, parallelize across source spaces.
[out]	resp	Forward solution matrix.
[out]	resp_grad	Gradient forward solution matrix.
[in]	bDoGRad	If true, also compute the gradient solution.

Returns: OK on success, FAIL on error.

Definition at line 2577 of file fwd_bem_model.cpp.

◆ correct_auto_elements()

void FwdBemModel::correct_auto_elements	(	MNELIB::MNESurface &	surf,
		Eigen::MatrixXf &	mat )

static

Correct the auto (self-coupling) elements of the linear collocation matrix.

Parameters

[in]	surf	The BEM surface.
[in,out]	mat	The coefficient matrix to correct (modified in-place).

Definition at line 645 of file fwd_bem_model.cpp.

◆ field_integrals()

void FwdBemModel::field_integrals	(	const Eigen::Vector3f &	from,
		MNELIB::MNETriangle &	to,
		double &	I1p,
		Eigen::Vector2d &	T,
		Eigen::Vector2d &	S1,
		Eigen::Vector2d &	S2,
		Eigen::Vector3d &	f0,
		Eigen::Vector3d &	fx,
		Eigen::Vector3d &	fy )

static

Compute the geometry integrals for the magnetic field from a triangle.

Parameters

[in]	from	Source point.
[in]	to	Destination triangle.
[out]	I1p	Monopolar integral.
[out]	T	Integral T.
[out]	S1	Integral S1.
[out]	S2	Integral S2.
[out]	f0	Integral f0.
[out]	fx	Integral fx.
[out]	fy	Integral fy.

Definition at line 1575 of file fwd_bem_model.cpp.

◆ fwd_bem_check_solids()

int FwdBemModel::fwd_bem_check_solids	(	const Eigen::MatrixXf &	angles,
		int	ntri1,
		int	ntri2,
		float	desired )

static

Verify that solid-angle sums match the expected value.

Parameters

[in]	angles	Solid-angle matrix.
[in]	ntri1	Row count.
[in]	ntri2	Column count.
[in]	desired	Expected solid-angle sum per row.

Returns: OK if all rows match within tolerance, FAIL otherwise.

Definition at line 959 of file fwd_bem_model.cpp.

◆ fwd_bem_compute_solution()

int FwdBemModel::fwd_bem_compute_solution ( int bem_method )

Compute the BEM solution matrix using the specified method.

Parameters

[in] bem_method BEM method (FWD_BEM_CONSTANT_COLL or FWD_BEM_LINEAR_COLL).

Returns: OK on success, FAIL on error.

Definition at line 1112 of file fwd_bem_model.cpp.

◆ fwd_bem_constant_collocation_solution()

int FwdBemModel::fwd_bem_constant_collocation_solution ( )

Compute the constant-collocation BEM solution for this model.

Returns: OK on success, FAIL on error.

Definition at line 1044 of file fwd_bem_model.cpp.

◆ fwd_bem_explain_method()

const QString & FwdBemModel::fwd_bem_explain_method ( int method )

static

Return a human-readable label for a BEM method.

Parameters

[in] method BEM method constant (FWD_BEM_CONSTANT_COLL / FWD_BEM_LINEAR_COLL).

Returns: Reference to a static string label.

Definition at line 244 of file fwd_bem_model.cpp.

◆ fwd_bem_explain_surface()

const QString & FwdBemModel::fwd_bem_explain_surface ( int kind )

static

Return a human-readable label for a BEM surface kind.

Parameters

[in] kind FIFF surface ID (e.g. FIFFV_BEM_SURF_ID_BRAIN).

Returns: Reference to a static string label.

Definition at line 231 of file fwd_bem_model.cpp.

◆ fwd_bem_field()

int FwdBemModel::fwd_bem_field	(	const Eigen::Vector3f &	rd,
		const Eigen::Vector3f &	Q,
		FwdCoilSet &	coils,
		Eigen::Ref< Eigen::VectorXf >	B,
		void *	client )

static

Callback: compute BEM magnetic fields at coils for a dipole.

Dispatches to fwd_bem_field_calc or fwd_bem_lin_field_calc based on the current BEM method. Matches the fwdFieldFunc signature.

Parameters

[in]	rd	Dipole position (3-element array).
[in]	Q	Dipole orientation (3-element array).
[in]	coils	MEG coil descriptors.
[out]	B	Output magnetic fields.
[in]	client	Opaque pointer to the FwdBemModel instance.

Returns: OK on success, FAIL on error.

Definition at line 2344 of file fwd_bem_model.cpp.

◆ fwd_bem_field_calc()

void FwdBemModel::fwd_bem_field_calc	(	const Eigen::Vector3f &	rd,
		const Eigen::Vector3f &	Q,
		FwdCoilSet &	coils,
		Eigen::Ref< Eigen::VectorXf >	B )

Compute BEM magnetic fields at coils using constant collocation.

Parameters

[in]	rd	Dipole position.
[in]	Q	Dipole orientation.
[in]	coils	MEG coil set.
[out]	B	Output magnetic fields (one value per coil).

Definition at line 2090 of file fwd_bem_model.cpp.

◆ fwd_bem_field_coeff()

Eigen::MatrixXf FwdBemModel::fwd_bem_field_coeff ( FwdCoilSet * coils )

Assemble the constant-collocation magnetic field coefficient matrix.

Parameters

[in] coils MEG coil set.

Returns: Coefficient matrix, or empty matrix on error.

Definition at line 1716 of file fwd_bem_model.cpp.

◆ fwd_bem_field_grad()

int FwdBemModel::fwd_bem_field_grad	(	const Eigen::Vector3f &	rd,
		const Eigen::Vector3f &	Q,
		FwdCoilSet &	coils,
		Eigen::Ref< Eigen::VectorXf >	Bval,
		Eigen::Ref< Eigen::VectorXf >	xgrad,
		Eigen::Ref< Eigen::VectorXf >	ygrad,
		Eigen::Ref< Eigen::VectorXf >	zgrad,
		void *	client )

static

Callback: compute BEM magnetic fields and position gradients at coils.

Matches the fwdFieldGradFunc signature for use in forward computation threads.

Parameters

[in]	rd	Dipole position (3-element array).
[in]	Q	Dipole orientation (3-element array).
[in]	coils	MEG coil definitions.
[out]	Bval	Output magnetic fields.
[out]	xgrad	Gradient with respect to x.
[out]	ygrad	Gradient with respect to y.
[out]	zgrad	Gradient with respect to z.
[in]	client	Opaque pointer to the FwdBemModel instance.

Returns: OK on success, FAIL on error.

Definition at line 2377 of file fwd_bem_model.cpp.

◆ fwd_bem_field_grad_calc()

void FwdBemModel::fwd_bem_field_grad_calc	(	const Eigen::Vector3f &	rd,
		const Eigen::Vector3f &	Q,
		FwdCoilSet &	coils,
		Eigen::Ref< Eigen::VectorXf >	xgrad,
		Eigen::Ref< Eigen::VectorXf >	ygrad,
		Eigen::Ref< Eigen::VectorXf >	zgrad )

Compute the gradient of BEM magnetic fields with respect to dipole position (constant collocation).

Parameters

[in]	rd	Dipole position.
[in]	Q	Dipole orientation.
[in]	coils	MEG coil set.
[out]	xgrad	Gradient with respect to x (one value per coil).
[out]	ygrad	Gradient with respect to y.
[out]	zgrad	Gradient with respect to z.

Definition at line 2154 of file fwd_bem_model.cpp.

◆ fwd_bem_find_surface()

MNESurface * FwdBemModel::fwd_bem_find_surface ( int kind )

Find a surface of the given kind in this BEM model.

Parameters

[in] kind FsSurface ID to look for.

Returns: Non-owning pointer to the surface, or nullptr if not found.

Definition at line 277 of file fwd_bem_model.cpp.

◆ fwd_bem_free_solution()

void FwdBemModel::fwd_bem_free_solution ( )

Release the potential solution matrix and associated workspace.

Resets solution, v0, sol_name, nsol, and bem_method to their default (empty / unknown) state.

Definition at line 204 of file fwd_bem_model.cpp.

◆ fwd_bem_homog_solution()

Eigen::MatrixXf FwdBemModel::fwd_bem_homog_solution	(	Eigen::MatrixXf &	solids,
		int	ntri )

static

Compute the homogeneous (single-layer) BEM solution.

Parameters

[in]	solids	Solid-angle coefficient matrix.
[in]	ntri	Number of triangles.

Returns: Solution matrix, or empty matrix on error.

Definition at line 889 of file fwd_bem_model.cpp.

◆ fwd_bem_inf_field()

float FwdBemModel::fwd_bem_inf_field	(	const Eigen::Vector3f &	rd,
		const Eigen::Vector3f &	Q,
		const Eigen::Vector3f &	rp,
		const Eigen::Vector3f &	dir )

static

Compute the infinite-medium magnetic field at a single point.

Returns the component of the magnetic field along the given direction, without the mu_0 / (4 pi) prefactor.

Parameters

[in]	rd	Dipole position.
[in]	Q	Dipole moment.
[in]	rp	Field point.
[in]	dir	Field direction of interest (unit vector).

Returns: The infinite-medium magnetic field component.

Definition at line 1160 of file fwd_bem_model.cpp.

◆ fwd_bem_inf_field_der()

float FwdBemModel::fwd_bem_inf_field_der	(	const Eigen::Vector3f &	rd,
		const Eigen::Vector3f &	Q,
		const Eigen::Vector3f &	rp,
		const Eigen::Vector3f &	dir,
		const Eigen::Vector3f &	comp )

static

Compute the derivative of the infinite-medium magnetic field with respect to dipole position.

Returns the field derivative without the mu_0 / (4 pi) prefactor.

Parameters

[in]	rd	Dipole position.
[in]	Q	Dipole moment.
[in]	rp	Field point.
[in]	dir	Field direction of interest (unit vector).
[in]	comp	Gradient component direction (unit vector).

Returns: The field derivative value.

Definition at line 2232 of file fwd_bem_model.cpp.

◆ fwd_bem_inf_pot()

float FwdBemModel::fwd_bem_inf_pot	(	const Eigen::Vector3f &	rd,
		const Eigen::Vector3f &	Q,
		const Eigen::Vector3f &	rp )

static

Compute the infinite-medium electric potential at a single point.

Returns the potential without the 1 / (4 pi sigma) prefactor.

Parameters

[in]	rd	Dipole position.
[in]	Q	Dipole moment.
[in]	rp	Potential evaluation point.

Returns: The infinite-medium electric potential.

Definition at line 1175 of file fwd_bem_model.cpp.

◆ fwd_bem_inf_pot_der()

float FwdBemModel::fwd_bem_inf_pot_der	(	const Eigen::Vector3f &	rd,
		const Eigen::Vector3f &	Q,
		const Eigen::Vector3f &	rp,
		const Eigen::Vector3f &	comp )

static

Compute the derivative of the infinite-medium electric potential with respect to dipole position.

Parameters

[in]	rd	Dipole position.
[in]	Q	Dipole moment.
[in]	rp	Potential evaluation point.
[in]	comp	Gradient component direction (unit vector).

Returns: The potential derivative value.

Definition at line 2250 of file fwd_bem_model.cpp.

◆ fwd_bem_ip_modify_solution()

void FwdBemModel::fwd_bem_ip_modify_solution	(	Eigen::MatrixXf &	solution,
		Eigen::MatrixXf &	ip_solution,
		float	ip_mult,
		int	nsurf,
		const Eigen::VectorXi &	ntri )

static

Modify the BEM solution with the isolated-problem (IP) approach.

Applies the correction for the innermost surface conductivity jump (the "isolated problem" approach of Hamalainen and Sarvas, 1989).

Parameters

[in,out]	solution	The original solution matrix (modified in-place).
[in]	ip_solution	The isolated-problem solution matrix.
[in]	ip_mult	Conductivity ratio for the IP correction.
[in]	nsurf	Number of surfaces.
[in]	ntri	Triangle or node count per surface.

Definition at line 902 of file fwd_bem_model.cpp.

◆ fwd_bem_lin_field_calc()

void FwdBemModel::fwd_bem_lin_field_calc	(	const Eigen::Vector3f &	rd,
		const Eigen::Vector3f &	Q,
		FwdCoilSet &	coils,
		Eigen::Ref< Eigen::VectorXf >	B )

Compute BEM magnetic fields at coils using linear collocation.

Parameters

[in]	rd	Dipole position.
[in]	Q	Dipole orientation.
[in]	coils	MEG coil set.
[out]	B	Output magnetic fields (one value per coil).

Definition at line 2028 of file fwd_bem_model.cpp.

◆ fwd_bem_lin_field_coeff()

Eigen::MatrixXf FwdBemModel::fwd_bem_lin_field_coeff	(	FwdCoilSet *	coils,
		int	method )

Assemble the linear-collocation magnetic field coefficient matrix.

Parameters

[in]	coils	MEG coil set.
[in]	method	Integration method (FWD_BEM_LIN_FIELD_SIMPLE, _FERGUSON, or _URANKAR).

Returns: Coefficient matrix, or empty matrix on error.

Definition at line 1900 of file fwd_bem_model.cpp.

◆ fwd_bem_lin_field_grad_calc()

void FwdBemModel::fwd_bem_lin_field_grad_calc	(	const Eigen::Vector3f &	rd,
		const Eigen::Vector3f &	Q,
		FwdCoilSet &	coils,
		Eigen::Ref< Eigen::VectorXf >	xgrad,
		Eigen::Ref< Eigen::VectorXf >	ygrad,
		Eigen::Ref< Eigen::VectorXf >	zgrad )

Compute the gradient of BEM magnetic fields with respect to dipole position (linear collocation).

Parameters

[in]	rd	Dipole position.
[in]	Q	Dipole orientation.
[in]	coils	MEG coil set.
[out]	xgrad	Gradient with respect to x (one value per coil).
[out]	ygrad	Gradient with respect to y.
[out]	zgrad	Gradient with respect to z.

Definition at line 2267 of file fwd_bem_model.cpp.

◆ fwd_bem_lin_pot_calc()

void FwdBemModel::fwd_bem_lin_pot_calc	(	const Eigen::Vector3f &	rd,
		const Eigen::Vector3f &	Q,
		FwdCoilSet *	els,
		int	all_surfs,
		Eigen::Ref< Eigen::VectorXf >	pot )

Compute BEM potentials at electrodes using linear collocation.

Parameters

[in]	rd	Dipole position.
[in]	Q	Dipole orientation.
[in]	els	Electrode set.
[in]	all_surfs	If non-zero, compute on all surfaces.
[out]	pot	Output potentials (one value per electrode).

Definition at line 1324 of file fwd_bem_model.cpp.

◆ fwd_bem_lin_pot_coeff()

Eigen::MatrixXf FwdBemModel::fwd_bem_lin_pot_coeff ( const std::vector< MNELIB::MNESurface * > & surfs )

static

Assemble the full linear-collocation potential coefficient matrix.

Parameters

[in] surfs Vector of BEM surfaces.

Returns: Coefficient matrix (rows = nodes, columns = nodes).

Definition at line 713 of file fwd_bem_model.cpp.

◆ fwd_bem_lin_pot_grad_calc()

void FwdBemModel::fwd_bem_lin_pot_grad_calc	(	const Eigen::Vector3f &	rd,
		const Eigen::Vector3f &	Q,
		FwdCoilSet *	els,
		int	all_surfs,
		Eigen::Ref< Eigen::VectorXf >	xgrad,
		Eigen::Ref< Eigen::VectorXf >	ygrad,
		Eigen::Ref< Eigen::VectorXf >	zgrad )

Compute the gradient of BEM potentials with respect to dipole position (linear collocation).

Parameters

[in]	rd	Dipole position.
[in]	Q	Dipole orientation.
[in]	els	Electrode set.
[in]	all_surfs	If non-zero, compute on all surfaces.
[out]	xgrad	Gradient with respect to x (one value per electrode).
[out]	ygrad	Gradient with respect to y.
[out]	zgrad	Gradient with respect to z.

Definition at line 1367 of file fwd_bem_model.cpp.

◆ fwd_bem_linear_collocation_solution()

int FwdBemModel::fwd_bem_linear_collocation_solution ( )

Compute the linear-collocation BEM solution for this model.

Returns: OK on success, FAIL on error.

Definition at line 779 of file fwd_bem_model.cpp.

◆ fwd_bem_load_homog_surface()

FwdBemModel::UPtr FwdBemModel::fwd_bem_load_homog_surface ( const QString & name )

static

Load a single-layer (homogeneous) BEM model from a FIFF file.

Convenience wrapper that loads only the inner skull surface.

Parameters

[in] name Path to the BEM FIFF file.

Returns: BEM model, or nullptr on failure.

Definition at line 356 of file fwd_bem_model.cpp.

◆ fwd_bem_load_recompute_solution()

int FwdBemModel::fwd_bem_load_recompute_solution	(	const QString &	name,
		int	bem_method,
		int	force_recompute )

Load a BEM solution from file, recomputing if necessary.

Attempts to read the pre-computed solution; if it is missing or force_recompute is set, computes a fresh solution.

Parameters

[in]	name	Path to the BEM model file.
[in]	bem_method	Required BEM method.
[in]	force_recompute	If non-zero, always recompute the solution.

Returns: OK on success, FAIL on error.

Definition at line 1132 of file fwd_bem_model.cpp.

◆ fwd_bem_load_solution()

int FwdBemModel::fwd_bem_load_solution	(	const QString &	name,
		int	bem_method )

Load a pre-computed BEM solution from a FIFF file.

Reads the solution matrix from disk and stores it in this model. The solution must match the requested BEM method.

Parameters

[in]	name	Path to the solution FIFF file.
[in]	bem_method	Required BEM method (FWD_BEM_CONSTANT_COLL or FWD_BEM_LINEAR_COLL).

Returns: true if loaded, false if not found, FAIL on error.

Definition at line 376 of file fwd_bem_model.cpp.

◆ fwd_bem_load_surfaces()

FwdBemModel::UPtr FwdBemModel::fwd_bem_load_surfaces	(	const QString &	name,
		const std::vector< int > &	kinds )

static

Load BEM surfaces of specified kinds from a FIFF file.

Parameters

[in]	name	Path to the BEM FIFF file.
[in]	kinds	FsSurface IDs to load (e.g. FIFFV_BEM_SURF_ID_BRAIN).

Returns: BEM model containing the requested surfaces, or nullptr on failure.

Definition at line 288 of file fwd_bem_model.cpp.

◆ fwd_bem_load_three_layer_surfaces()

FwdBemModel::UPtr FwdBemModel::fwd_bem_load_three_layer_surfaces ( const QString & name )

static

Load a three-layer BEM model (scalp, outer skull, inner skull) from a FIFF file.

Parameters

[in] name Path to the BEM FIFF file.

Returns: BEM model, or nullptr on failure.

Definition at line 366 of file fwd_bem_model.cpp.

◆ fwd_bem_make_bem_sol_name()

QString FwdBemModel::fwd_bem_make_bem_sol_name ( const QString & name )

static

Build a standard BEM solution file name from a model name.

Parameters

[in] name Base BEM file name.

Returns: The derived solution file name.

Definition at line 215 of file fwd_bem_model.cpp.

◆ fwd_bem_multi_solution()

Eigen::MatrixXf FwdBemModel::fwd_bem_multi_solution	(	Eigen::MatrixXf &	solids,
		const Eigen::MatrixXf *	gamma,
		int	nsurf,
		const Eigen::VectorXi &	ntri )

static

Compute the multi-surface BEM solution from solid-angle coefficients.

Applies the deflation technique and LU decomposition to produce the final BEM solution matrix for a multi-compartment model.

Parameters

[in]	solids	Solid-angle coefficient matrix.
[in]	gamma	Conductivity-ratio coupling matrix (nullptr for homogeneous).
[in]	nsurf	Number of surfaces.
[in]	ntri	Triangle or node count per surface.

Returns: Solution matrix, or empty matrix on error.

Definition at line 848 of file fwd_bem_model.cpp.

◆ fwd_bem_one_lin_field_coeff_ferg()

void FwdBemModel::fwd_bem_one_lin_field_coeff_ferg	(	const Eigen::Vector3f &	dest,
		const Eigen::Vector3f &	dir,
		MNELIB::MNETriangle &	tri,
		Eigen::Vector3d &	res )

static

Compute linear field coefficients using the Ferguson method.

Parameters

[in]	dest	Field point.
[in]	dir	Field direction of interest (unit vector).
[in]	tri	Destination triangle.
[out]	res	Output coefficients for the three triangle vertices.

Definition at line 1794 of file fwd_bem_model.cpp.

◆ fwd_bem_one_lin_field_coeff_simple()

void FwdBemModel::fwd_bem_one_lin_field_coeff_simple	(	const Eigen::Vector3f &	dest,
		const Eigen::Vector3f &	normal,
		MNELIB::MNETriangle &	source,
		Eigen::Vector3d &	res )

static

Compute linear field coefficients using the simple (direct) method.

Parameters

[in]	dest	Destination field point.
[in]	normal	Field direction of interest (unit vector).
[in]	source	Source triangle.
[out]	res	Output coefficients for the three triangle vertices.

Definition at line 1884 of file fwd_bem_model.cpp.

◆ fwd_bem_one_lin_field_coeff_uran()

void FwdBemModel::fwd_bem_one_lin_field_coeff_uran	(	const Eigen::Vector3f &	dest,
		const Eigen::Vector3f &	dir,
		MNELIB::MNETriangle &	tri,
		Eigen::Vector3d &	res )

static

Compute linear field coefficients using the Urankar method.

Parameters

[in]	dest	Field point.
[in]	dir	Field direction of interest (unit vector).
[in]	tri	Destination triangle.
[out]	res	Output coefficients for the three triangle vertices.

Definition at line 1856 of file fwd_bem_model.cpp.

◆ fwd_bem_pot_calc()

void FwdBemModel::fwd_bem_pot_calc	(	const Eigen::Vector3f &	rd,
		const Eigen::Vector3f &	Q,
		FwdCoilSet *	els,
		int	all_surfs,
		Eigen::Ref< Eigen::VectorXf >	pot )

Compute BEM potentials at electrodes using constant collocation.

Parameters

[in]	rd	Dipole position.
[in]	Q	Dipole orientation.
[in]	els	Electrode set.
[in]	all_surfs	If non-zero, compute on all surfaces.
[out]	pot	Output potentials (one value per electrode).

Definition at line 1420 of file fwd_bem_model.cpp.

◆ fwd_bem_pot_els()

int FwdBemModel::fwd_bem_pot_els	(	const Eigen::Vector3f &	rd,
		const Eigen::Vector3f &	Q,
		FwdCoilSet &	els,
		Eigen::Ref< Eigen::VectorXf >	pot,
		void *	client )

static

Callback: compute BEM potentials at electrodes for a dipole.

Matches the fwdFieldFunc signature for use in forward computation threads.

Parameters

[in]	rd	Dipole position (3-element array).
[in]	Q	Dipole orientation (3-element array).
[in]	els	Electrode descriptors.
[out]	pot	Output potentials.
[in]	client	Opaque pointer to the FwdBemModel instance.

Returns: OK on success, FAIL on error.

Definition at line 1463 of file fwd_bem_model.cpp.

◆ fwd_bem_pot_grad_calc()

void FwdBemModel::fwd_bem_pot_grad_calc	(	const Eigen::Vector3f &	rd,
		const Eigen::Vector3f &	Q,
		FwdCoilSet *	els,
		int	all_surfs,
		Eigen::Ref< Eigen::VectorXf >	xgrad,
		Eigen::Ref< Eigen::VectorXf >	ygrad,
		Eigen::Ref< Eigen::VectorXf >	zgrad )

Compute the gradient of BEM potentials with respect to dipole position (constant collocation).

Parameters

[in]	rd	Dipole position.
[in]	Q	Dipole orientation.
[in]	els	Electrode set.
[in]	all_surfs	If non-zero, compute on all surfaces.
[out]	xgrad	Gradient with respect to x (one value per electrode).
[out]	ygrad	Gradient with respect to y.
[out]	zgrad	Gradient with respect to z.

Definition at line 1270 of file fwd_bem_model.cpp.

◆ fwd_bem_pot_grad_els()

int FwdBemModel::fwd_bem_pot_grad_els	(	const Eigen::Vector3f &	rd,
		const Eigen::Vector3f &	Q,
		FwdCoilSet &	els,
		Eigen::Ref< Eigen::VectorXf >	pot,
		Eigen::Ref< Eigen::VectorXf >	xgrad,
		Eigen::Ref< Eigen::VectorXf >	ygrad,
		Eigen::Ref< Eigen::VectorXf >	zgrad,
		void *	client )

static

Callback: compute BEM potentials and position gradients at electrodes.

Matches the fwdFieldGradFunc signature for use in forward computation threads.

Parameters

[in]	rd	Dipole position (3-element array).
[in]	Q	Dipole orientation (3-element array).
[in]	els	Electrode descriptors.
[out]	pot	Output potentials.
[out]	xgrad	Gradient with respect to x.
[out]	ygrad	Gradient with respect to y.
[out]	zgrad	Gradient with respect to z.
[in]	client	Opaque pointer to the FwdBemModel instance.

Returns: OK on success, FAIL on error.

Definition at line 1498 of file fwd_bem_model.cpp.

◆ fwd_bem_set_head_mri_t()

int FwdBemModel::fwd_bem_set_head_mri_t ( const FIFFLIB::FiffCoordTrans & t )

Set the Head-to-MRI coordinate transform for this BEM model.

Parameters

[in] t The head-to-MRI coordinate transformation.

Returns: OK on success, FAIL on error.

Definition at line 467 of file fwd_bem_model.cpp.

◆ fwd_bem_solid_angles()

Eigen::MatrixXf FwdBemModel::fwd_bem_solid_angles ( const std::vector< MNELIB::MNESurface * > & surfs )

static

Compute the solid-angle matrix for all BEM surfaces.

Parameters

[in] surfs Vector of BEM surfaces.

Returns: Solid-angle matrix, or empty matrix on error.

Definition at line 993 of file fwd_bem_model.cpp.

◆ fwd_bem_specify_coils()

int FwdBemModel::fwd_bem_specify_coils ( FwdCoilSet * coils )

Precompute the coil-specific BEM solution for MEG.

Builds the coil-specific solution matrix by multiplying the BEM solution with the field coefficients.

Parameters

[in] coils MEG coil set to prepare.

Returns: OK on success, FAIL on error.

Definition at line 1990 of file fwd_bem_model.cpp.

◆ fwd_bem_specify_els()

int FwdBemModel::fwd_bem_specify_els ( FwdCoilSet * els )

Precompute the electrode-specific BEM solution.

Builds the coil-specific solution matrix for EEG electrodes by multiplying the BEM solution with infinite-medium potentials.

Parameters

[in] els Electrode (coil) set to prepare.

Returns: OK on success, FAIL on error.

Definition at line 1187 of file fwd_bem_model.cpp.

◆ fwd_mag_dipole_field()

int FwdBemModel::fwd_mag_dipole_field	(	const Eigen::Vector3f &	rm,
		const Eigen::Vector3f &	M,
		FwdCoilSet &	coils,
		Eigen::Ref< Eigen::VectorXf >	Bval,
		void *	client )

static

Callback: compute the magnetic field of a magnetic dipole at coils.

Parameters

[in]	rm	Dipole position (in the same coordinate system as the coils).
[in]	M	Dipole moment components (xyz).
[in]	coils	MEG coil definitions.
[out]	Bval	Output magnetic fields.
[in]	client	Opaque pointer to client data (unused, may be nullptr).

Returns: OK on success, FAIL on error.

Definition at line 3338 of file fwd_bem_model.cpp.

◆ fwd_mag_dipole_field_vec()

int FwdBemModel::fwd_mag_dipole_field_vec	(	const Eigen::Vector3f &	rm,
		FwdCoilSet &	coils,
		Eigen::Ref< Eigen::MatrixXf >	Bval,
		void *	client )

static

Callback: compute the vector magnetic field of a magnetic dipole at coils.

Returns one row per cardinal dipole direction (x, y, z).

Parameters

[in]	rm	Dipole position (3-element array).
[in]	coils	MEG coil definitions.
[out]	Bval	Output fields (3 x ncoil matrix, row-major).
[in]	client	Opaque pointer to client data (unused, may be nullptr).

Returns: OK on success, FAIL on error.

Definition at line 3375 of file fwd_bem_model.cpp.

◆ fwd_sphere_field()

int FwdBemModel::fwd_sphere_field	(	const Eigen::Vector3f &	rd,
		const Eigen::Vector3f &	Q,
		FwdCoilSet &	coils,
		Eigen::Ref< Eigen::VectorXf >	Bval,
		void *	client )

static

Callback: compute the spherical-model magnetic field at coils.

Matches the fwdFieldFunc signature.

Parameters

[in]	rd	Dipole position (3-element array).
[in]	Q	Dipole components (xyz).
[in]	coils	MEG coil definitions.
[out]	Bval	Output magnetic fields.
[in]	client	Opaque pointer to client data (sphere model origin).

Returns: OK on success, FAIL on error.

Definition at line 3006 of file fwd_bem_model.cpp.

◆ fwd_sphere_field_grad()

int FwdBemModel::fwd_sphere_field_grad	(	const Eigen::Vector3f &	rd,
		const Eigen::Vector3f &	Q,
		FwdCoilSet &	coils,
		Eigen::Ref< Eigen::VectorXf >	Bval,
		Eigen::Ref< Eigen::VectorXf >	xgrad,
		Eigen::Ref< Eigen::VectorXf >	ygrad,
		Eigen::Ref< Eigen::VectorXf >	zgrad,
		void *	client )

static

Callback: compute the spherical-model magnetic field and its position gradient at coils.

Matches the fwdFieldGradFunc signature.

Parameters

[in]	rd	Dipole position (3-element array).
[in]	Q	Dipole components (xyz).
[in]	coils	MEG coil definitions.
[out]	Bval	Output magnetic fields.
[out]	xgrad	Gradient with respect to x.
[out]	ygrad	Gradient with respect to y.
[out]	zgrad	Gradient with respect to z.
[in]	client	Opaque pointer to client data.

Returns: OK on success, FAIL on error.

Definition at line 3206 of file fwd_bem_model.cpp.

◆ fwd_sphere_field_vec()

int FwdBemModel::fwd_sphere_field_vec	(	const Eigen::Vector3f &	rd,
		FwdCoilSet &	coils,
		Eigen::Ref< Eigen::MatrixXf >	Bval,
		void *	client )

static

Callback: compute the spherical-model vector magnetic field at coils.

Returns one row per cardinal dipole direction (x, y, z). Matches the fwdVecFieldFunc signature.

Parameters

[in]	rd	Dipole position (3-element array).
[in]	coils	MEG coil definitions.
[out]	Bval	Output fields (3 x ncoil matrix, row-major).
[in]	client	Opaque pointer to client data.

Returns: OK on success, FAIL on error.

Definition at line 3102 of file fwd_bem_model.cpp.

◆ get_int()

int FwdBemModel::get_int	(	FIFFLIB::FiffStream::SPtr &	stream,
		const FIFFLIB::FiffDirNode::SPtr &	node,
		int	what,
		int *	res )

static

Read an integer tag from a FIFF node.

Definition at line 258 of file fwd_bem_model.cpp.

◆ lin_pot_coeff()

void FwdBemModel::lin_pot_coeff	(	const Eigen::Vector3f &	from,
		MNELIB::MNETriangle &	to,
		Eigen::Vector3d &	omega )

static

Compute the linear potential coefficients for one source-destination pair.

Parameters

[in]	from	Source point.
[in]	to	Destination triangle.
[out]	omega	Output coefficients for the three triangle vertices.

Definition at line 550 of file fwd_bem_model.cpp.

◆ make_guesses()

MNESurface::UPtr FwdBemModel::make_guesses	(	MNELIB::MNESurface *	guess_surf,
		float	guessrad,
		const Eigen::Vector3f &	guess_r0,
		float	grid,
		float	exclude,
		float	mindist )

static

Generate a set of dipole guess locations inside a boundary surface.

Creates an evenly-spaced grid of candidate source locations, optionally excluding points too close to the center of mass or outside the boundary.

Parameters

[in]	guess_surf	Predefined boundary surface for the guesses (may be nullptr).
[in]	guessrad	Radius for a spherical boundary if guess_surf is nullptr.
[in]	guess_r0	Origin for the spherical boundary.
[in]	grid	Spacing between guess points (meters).
[in]	exclude	Exclude points closer than this to the CM of the boundary.
[in]	mindist	Minimum distance from the boundary surface.

Returns: FsSurface containing the guess locations, or nullptr on failure.

Definition at line 488 of file fwd_bem_model.cpp.

◆ meg_eeg_fwd_one_source_space()

void FwdBemModel::meg_eeg_fwd_one_source_space ( FwdThreadArg * arg )

static

Thread worker: compute the forward solution for one source space.

Used as a thread entry point; the argument is cast to the appropriate worker struct internally.

Parameters

[in] arg Per-thread work descriptor.

Definition at line 2419 of file fwd_bem_model.cpp.

◆ one_field_coeff()

double FwdBemModel::one_field_coeff	(	const Eigen::Vector3f &	dest,
		const Eigen::Vector3f &	normal,
		MNELIB::MNETriangle &	tri )

static

Compute the constant-collocation magnetic field coefficient for one triangle.

Parameters

[in]	dest	Destination field point.
[in]	normal	Field direction of interest (unit vector).
[in]	tri	Source triangle.

Returns: The field coefficient.

Definition at line 1691 of file fwd_bem_model.cpp.

Member Data Documentation

◆ bem_method

int FWDLIB::FwdBemModel::bem_method

Approximation method (FWD_BEM_CONSTANT_COLL or FWD_BEM_LINEAR_COLL).

Definition at line 1037 of file fwd_bem_model.h.

◆ field_mult

Eigen::VectorXf FWDLIB::FwdBemModel::field_mult

Magnetic-field multipliers (length nsurf).

Definition at line 1035 of file fwd_bem_model.h.

◆ gamma

Eigen::MatrixXf FWDLIB::FwdBemModel::gamma

Conductivity-ratio coupling matrix (nsurf x nsurf).

Definition at line 1033 of file fwd_bem_model.h.

◆ head_mri_t

FIFFLIB::FiffCoordTrans FWDLIB::FwdBemModel::head_mri_t

Head-to-MRI coordinate transform.

Definition at line 1044 of file fwd_bem_model.h.

◆ ip_approach_limit

float FWDLIB::FwdBemModel::ip_approach_limit

Threshold for isolated-problem approach.

Definition at line 1046 of file fwd_bem_model.h.

◆ MAG_FACTOR

double FWDLIB::FwdBemModel::MAG_FACTOR = 1e-7

staticconstexpr

Magnetic constant mu_0 / (4 * pi).

Definition at line 746 of file fwd_bem_model.h.

◆ np

Eigen::VectorXi FWDLIB::FwdBemModel::np

Vertex count per surface (length nsurf).

Definition at line 1029 of file fwd_bem_model.h.

◆ nsol

int FWDLIB::FwdBemModel::nsol

Dimension of the solution matrix.

Definition at line 1042 of file fwd_bem_model.h.

◆ nsurf

int FWDLIB::FwdBemModel::nsurf

Number of interface surfaces.

Definition at line 1030 of file fwd_bem_model.h.

◆ ntri

Eigen::VectorXi FWDLIB::FwdBemModel::ntri

Triangle count per surface (length nsurf).

Definition at line 1028 of file fwd_bem_model.h.

◆ sigma

Eigen::VectorXf FWDLIB::FwdBemModel::sigma

Conductivity of each layer (length nsurf).

Definition at line 1032 of file fwd_bem_model.h.

◆ sol_name

QString FWDLIB::FwdBemModel::sol_name

File from which the solution was loaded.

Definition at line 1038 of file fwd_bem_model.h.

◆ solution

Eigen::MatrixXf FWDLIB::FwdBemModel::solution

Potential solution matrix (nsol x nsol).

Definition at line 1040 of file fwd_bem_model.h.

◆ source_mult

Eigen::VectorXf FWDLIB::FwdBemModel::source_mult

Infinite-medium potential multipliers (length nsurf).

Definition at line 1034 of file fwd_bem_model.h.

◆ surf_name

QString FWDLIB::FwdBemModel::surf_name

File from which surfaces were loaded.

Definition at line 1024 of file fwd_bem_model.h.

◆ surfs

std::vector<std::shared_ptr<MNELIB::MNESurface> > FWDLIB::FwdBemModel::surfs

Interface surfaces, outermost first.

Definition at line 1026 of file fwd_bem_model.h.

◆ use_ip_approach

bool FWDLIB::FwdBemModel::use_ip_approach

Whether the isolated-problem approach is active.

Definition at line 1047 of file fwd_bem_model.h.

◆ v0

Eigen::VectorXf FWDLIB::FwdBemModel::v0

Workspace for infinite-medium potentials (length nsol).

Definition at line 1041 of file fwd_bem_model.h.

The documentation for this class was generated from the following files:

src/libraries/fwd/fwd_bem_model.h
src/libraries/fwd/fwd_bem_model.cpp

Public Types

Public Member Functions

Static Public Member Functions

Public Attributes

Static Public Attributes

Detailed Description

Member Typedef Documentation

◆ linFieldIntFunc

◆ UPtr

Constructor & Destructor Documentation

◆ FwdBemModel()

◆ ~FwdBemModel()

Member Function Documentation

◆ calc_beta()

◆ calc_f()

◆ calc_gamma()

◆ calc_magic()

◆ compute_forward_eeg()

◆ compute_forward_meg()

◆ correct_auto_elements()

◆ field_integrals()

◆ fwd_bem_check_solids()

◆ fwd_bem_compute_solution()

◆ fwd_bem_constant_collocation_solution()

◆ fwd_bem_explain_method()

◆ fwd_bem_explain_surface()

◆ fwd_bem_field()

◆ fwd_bem_field_calc()

◆ fwd_bem_field_coeff()

◆ fwd_bem_field_grad()

◆ fwd_bem_field_grad_calc()

◆ fwd_bem_find_surface()

◆ fwd_bem_free_solution()

◆ fwd_bem_homog_solution()

◆ fwd_bem_inf_field()

◆ fwd_bem_inf_field_der()

◆ fwd_bem_inf_pot()

◆ fwd_bem_inf_pot_der()

◆ fwd_bem_ip_modify_solution()

◆ fwd_bem_lin_field_calc()

◆ fwd_bem_lin_field_coeff()

◆ fwd_bem_lin_field_grad_calc()

◆ fwd_bem_lin_pot_calc()

◆ fwd_bem_lin_pot_coeff()

◆ fwd_bem_lin_pot_grad_calc()

◆ fwd_bem_linear_collocation_solution()

◆ fwd_bem_load_homog_surface()

◆ fwd_bem_load_recompute_solution()

◆ fwd_bem_load_solution()

◆ fwd_bem_load_surfaces()

◆ fwd_bem_load_three_layer_surfaces()

◆ fwd_bem_make_bem_sol_name()

◆ fwd_bem_multi_solution()

◆ fwd_bem_one_lin_field_coeff_ferg()

◆ fwd_bem_one_lin_field_coeff_simple()

◆ fwd_bem_one_lin_field_coeff_uran()

◆ fwd_bem_pot_calc()

◆ fwd_bem_pot_els()

◆ fwd_bem_pot_grad_calc()

◆ fwd_bem_pot_grad_els()

◆ fwd_bem_set_head_mri_t()

◆ fwd_bem_solid_angles()

◆ fwd_bem_specify_coils()

◆ fwd_bem_specify_els()

◆ fwd_mag_dipole_field()

◆ fwd_mag_dipole_field_vec()

◆ fwd_sphere_field()

◆ fwd_sphere_field_grad()

◆ fwd_sphere_field_vec()

◆ get_int()

◆ lin_pot_coeff()

◆ make_guesses()

◆ meg_eeg_fwd_one_source_space()

◆ one_field_coeff()

Member Data Documentation

◆ bem_method

◆ field_mult

◆ gamma

◆ head_mri_t

◆ ip_approach_limit