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FwdCompData

Namespace: FWDLIB  ·  Library: Forward Library

#include <fwd/fwd_comp_data.h>

class FWDLIB::FwdCompData

Implements the Forward Compensation Data description (replaces fwdCompData / fwdCompDataRec from MNE-C fwd_comp_data.h).

CTF / 4D software-gradiometer wrapper that re-evaluates the primary field callback on a separate reference-coil set and subtracts the linear combination k·B_ref from the primary field to mirror the compensation already applied to the recorded data.

Public Methods​

FwdCompData()​

Constructs the Forward Compensation Data.

~FwdCompData()​

Destroys the Forward Compensation Data.

Static Methods​

fwd_comp_field(rd, Q, coils, res, client)​

Calculate the compensated field for one dipole component.

Parameters:

  • rd : const Eigen::Vector3f & Dipole position.

  • Q : const Eigen::Vector3f & Dipole moment direction.

  • coils : FwdCoilSet & Coil definitions.

  • res : Eigen::Ref< Eigen::VectorXf > Result vector.

  • client : *void ** Pointer to FwdCompData.

Returns:

  • int — OK on success, FAIL on error.

fwd_make_ctf_comp_coils(set, coils, comp_coils)​

Set up CTF compensation coils for field computations.

Parameters:

Returns:

  • int — OK on success, FAIL on error.

fwd_make_comp_data(set, coils, comp_coils, field, vec_field, field_grad, client)​

Compose a compensation data set.

Parameters:

  • set : *MNECTFCompDataSet ** CTF compensation data read from file.

  • coils : *FwdCoilSet ** Principal coil set.

  • comp_coils : *FwdCoilSet ** Compensation coils.

  • field : fwdFieldFunc Field computation function (single dipole component).

  • vec_field : fwdVecFieldFunc Vector field computation function (all components).

  • field_grad : fwdFieldGradFunc Field and gradient computation function.

  • client : *void ** Client data passed to the computation functions.

Returns:

fwd_comp_field_vec(rd, coils, res, client)​

Calculate the compensated field for all three dipole components.

Parameters:

  • rd : const Eigen::Vector3f & Dipole position.

  • coils : FwdCoilSet & Coil definitions.

  • res : Eigen::Ref< Eigen::MatrixXf > Result matrix (3 x ncoil).

  • client : *void ** Pointer to FwdCompData.

Returns:

  • int — OK on success, FAIL on error.

fwd_comp_field_grad(rd, Q, coils, res, xgrad, ygrad, zgrad, client)​

Calculate the compensated field and gradient for one dipole component.

Parameters:

  • rd : const Eigen::Vector3f & Dipole position.

  • Q : const Eigen::Vector3f & Dipole moment direction.

  • coils : FwdCoilSet & Coil definitions.

  • res : Eigen::Ref< Eigen::VectorXf > Result vector.

  • xgrad : Eigen::Ref< Eigen::VectorXf > X-gradient result.

  • ygrad : Eigen::Ref< Eigen::VectorXf > Y-gradient result.

  • zgrad : Eigen::Ref< Eigen::VectorXf > Z-gradient result.

  • client : *void ** Pointer to FwdCompData.

Returns:

  • int — OK on success, FAIL on error.

Example​

No example of its own: CTF compensation wrapper that FwdBemModel builds for compensated coil sets during ComputeFwd; callers reach it through ComputeFwd.

It is exercised by:

src/examples/ex_fwd_api/main.cpp
// mne_forward_solution --meg --eeg --accurate --label V1-lh.label with sphere models instead of a BEM
const QString label = tmp.filePath("V1-lh.label"); // the hemisphere is taken from the "-lh.label" suffix
QFile::copy(data + "/subjects/sample/label/lh.V1.label", label);
auto settings = std::make_shared<ComputeFwdSettings>();
settings->include_meg = true;
settings->include_eeg = true;
settings->accurate = true;
settings->srcname = data + "/subjects/sample/bem/sample-oct-6-src.fif";
settings->measname = rawFile.fileName();
settings->mriname = data + "/MEG/sample/all-trans.fif";
settings->r0 = origin;
settings->eeg_sphere_rad = 0.09f;
settings->mindist = 0.0f;
settings->filter_spaces = false;
settings->labels = {label};
settings->nlabel = 1;
settings->solname = tmp.filePath("V1-fwd.fif");
settings->pFiffInfo = QSharedPointer<FiffInfo>::create(raw.info);
settings->checkIntegrity();
auto fwd = std::make_shared<ComputeFwd>(settings)->calculateFwd();
QFile solFile(settings->solname);
fwd->write(solFile);

From ex_fwd_api.

Authors of this file​