MaxwellMovementComp

Namespace: RTPROCESSINGLIB  ·  Library: DSP Library

Python equivalent

mne.preprocessing.maxwell_filter (head_pos) in MNE-Python.

#include <dsp/maxwell_movement_comp.h>

class UTILSLIB::MaxwellMovementComp

Maxwell movement compensation using SSS.

src/examples/ex_dsp_maxwell/main.cpp

QList<HeadPosEntry> headPos(1); // one position from t = 0: identity rotation, no translation
MaxwellMoveCompParams moveParams;
moveParams.origin = params.origin;
const MatrixXd compensated = MaxwellMovementComp::apply(data, info, headPos, 1.0, moveParams);

QTemporaryDir dir;
const QString posPath = dir.filePath("head.pos"); // same columns as mne.chpi.write_head_pos
const bool posWritten = MaxwellMovementComp::writeHeadPos(posPath, headPos);
const QList<HeadPosEntry> posBack = MaxwellMovementComp::readHeadPos(posPath);

---

Static Methods

apply(matData, fiffInfo, headPos, dSFreq, params)

Apply movement compensation via SSS.

For each time segment (defined by headPos entries), the data is: Projected into SSS multipole space using the actual head position.

Reconstructed at the reference head position.

Parameters:

• matData : const Eigen::MatrixXd & Full sensor data (n_channels × n_samples).

• fiffInfo : const FiffInfo & Measurement info (channel positions, etc.).

• headPos : const QList< HeadPosEntry > & Head positions over time (from cHPI).

• dSFreq : double Sampling frequency (Hz).

• params : const MaxwellMoveCompParams & Compensation parameters.

Returns:

• Eigen::MatrixXd — Movement-compensated data (n_channels × n_samples).

---

readHeadPos(sPath)

Read head positions from a file.

File format: whitespace-separated columns per line: time q1 q2 q3 tx ty tz gof

Parameters:

• sPath : const QString & Path to head position file.

Returns:

• QList< HeadPosEntry > — List of head position entries.

---

writeHeadPos(sPath, headPos)

Write head positions to a file.

Parameters:

• sPath : const QString & Output file path.

• headPos : const QList< HeadPosEntry > & Head positions to write.

Returns:

• bool — true if successful.

---

Example

• Full source: src/examples/ex_dsp_maxwell/main.cpp
• Build target: ex_dsp_maxwell (runs under CTest)
• Data: mne-cpp-test-data

Used in examples

ex_dsp_maxwell

DSP Maxwell filtering: SSS, bad-channel detection, movement compensation, fine calibration and cHPI removal.

src/examples/ex_dsp_maxwell/main.cpp, line 156

QList<HeadPosEntry> headPos(1); // one position from t = 0: identity rotation, no translation
MaxwellMoveCompParams moveParams;
moveParams.origin = params.origin;
const MatrixXd compensated = MaxwellMovementComp::apply(data, info, headPos, 1.0, moveParams);

Authors of this file

• Christoph Dinh <christoph.dinh@mne-cpp.org>