INVLIB::InvBeamformerCompute Class Reference

Core beamformer math. More...

#include <inv_beamformer_compute.h>

Static Public Member Functions
static bool	computeBeamformer (const Eigen::MatrixXd &G, const Eigen::MatrixXd &Cm, double reg, int nOrient, BeamformerWeightNorm weightNorm, BeamformerPickOri pickOri, bool reduceRank, BeamformerInversion invMethod, const Eigen::MatrixX3d &nn, Eigen::MatrixXd &W, Eigen::MatrixX3d &maxPowerOri)
static Eigen::VectorXd	computePower (const Eigen::MatrixXd &Cm, const Eigen::MatrixXd &W, int nOrient)
static Eigen::MatrixXd	symMatPow (const Eigen::MatrixXd &X, double p, bool reduceRank=false)

Detailed Description

Core beamformer math.

Shared computation routines used by both LCMV and DICS beamformers.

All methods are static — no state is kept between calls.

Definition at line 75 of file inv_beamformer_compute.h.

Member Function Documentation

computeBeamformer()

bool InvBeamformerCompute::computeBeamformer ( const Eigen::MatrixXd & G, const Eigen::MatrixXd & Cm, double reg, int nOrient, BeamformerWeightNorm weightNorm, BeamformerPickOri pickOri, bool reduceRank, BeamformerInversion invMethod, const Eigen::MatrixX3d & nn, Eigen::MatrixXd & W, Eigen::MatrixX3d & maxPowerOri )

static

Compute beamformer spatial filter weights from a leadfield and data covariance (or CSD).

This implements the core LCMV/DICS algorithm:

1. Regularize and invert covariance
2. Reshape leadfield per source (n_channels x n_orient)
3. Optionally reduce leadfield rank
4. Select orientation (max-power, normal, or keep all)
5. Invert denominator G^T Cm^{-1} G
6. Apply weight normalization

Parameters

[in]	G	Leadfield matrix (n_channels, n_sources * n_orient).
[in]	Cm	Data covariance or CSD matrix (n_channels, n_channels). Real-valued.
[in]	reg	Regularization parameter (fraction of trace to add, e.g. 0.05).
[in]	nOrient	Orientations per source: 1 (fixed) or 3 (free).
[in]	weightNorm	Weight normalization strategy.
[in]	pickOri	Orientation selection mode.
[in]	reduceRank	If true, reduce leadfield rank by 1 (for MEG sphere models).
[in]	invMethod	Denominator inversion strategy (matrix or scalar).
[in]	nn	Source normals (n_sources, 3). Used for max-power sign alignment.
[out]	W	Output spatial filter weights (n_sources * n_orient_out, n_channels).
[out]	maxPowerOri	Output max-power orientations (n_sources, 3). Empty if not max-power.

Returns

True on success.

Definition at line 193 of file inv_beamformer_compute.cpp.

computePower()

VectorXd InvBeamformerCompute::computePower ( const Eigen::MatrixXd & Cm, const Eigen::MatrixXd & W, int nOrient )

static

Compute source power from spatial filter weights and a data covariance / CSD matrix.

power_i = trace(W_i Cm W_i^T)

Parameters

[in]	Cm	Data covariance or CSD (n_channels, n_channels).
[in]	W	Spatial filter weights (n_sources * n_orient, n_channels).
[in]	nOrient	Orientations per source.

Returns

Source power vector (n_sources).

Definition at line 382 of file inv_beamformer_compute.cpp.

symMatPow()

MatrixXd InvBeamformerCompute::symMatPow ( const Eigen::MatrixXd & X, double p, bool reduceRank = false )

static

Symmetric matrix power: X^p via eigendecomposition.

Parameters

[in]	X	Symmetric matrix.
[in]	p	Power exponent (e.g. -1, -0.5).
[in]	reduceRank	Drop smallest eigenvalue before exponentiating.

Returns

X^p.

Definition at line 157 of file inv_beamformer_compute.cpp.

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

• src/libraries/inv/beamformer/inv_beamformer_compute.h
• src/libraries/inv/beamformer/inv_beamformer_compute.cpp