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InvHpiDataUpdater

Namespace: INVLIB  ·  Library: Inverse Library

#include <inv/inv_hpi_data_updater.h>

class INVLIB::InvHpiDataUpdater

This class brings all the data and objects used for HPI fitting into the right format.

Preprocesses raw HPI coil data (SSP projection, compensation, sinusoidal model fitting) before dipole localization

src/examples/ex_inv_hpi/main.cpp
InvHpiDataUpdater updater(info); // good MEG channels, their sensors and the digitised coil positions
updater.prepareDataAndProjectors(segment, MatrixXd::Identity(info->nchan, info->nchan));
// The coil frequencies are known but not their order; the first fit with bOrderFrequencies finds it.
const InvHpiModelParameters model(QVector<int>({154, 158, 161, 166}), info->sfreq, info->linefreq, true);
InvHpiFit hpi(updater.getSensors());
HpiFitResult fit;
hpi.fit(updater.getProjectedData(), updater.getProjectors(), model, updater.getHpiDigitizer(), true, fit);

Public Methods​

InvHpiDataUpdater(pFiffInfo)​

Constructs a InvHpiDataUpdater object.

Parameters:

  • pFiffInfo : const QSharedPointer<FiffInfo> Measurement info used to initialize channels, bads, HPI digitizer points and sensors.

checkForUpdate(pFiffInfo)​

Check if information in FiffInfo changed and update if necessary.

Parameters:

  • pFiffInfo : const QSharedPointer<FiffInfo> The FiffInfo to check for changes.

prepareDataAndProjectors(matData, matProjectors)​

Reduce data to only use good channels.

Parameters:

  • matData : const Eigen::MatrixXd & Data matrix (channels x samples).

  • matProjectors : const Eigen::MatrixXd & The projector matrix.

getChannels()​

inline get functions for private member variables.

Returns:

  • const QList< FiffChInfo > & — Const reference to the channel list with bad channels excluded.

getProjectors()​

getHpiDigitizer()​

getData()​

getProjectedData()​

getSensors()​

Example​

Used in examples​

ex_inv_hpi​

Inverse library: continuous head position (HPI) fitting.

src/examples/ex_inv_hpi/main.cpp, line 106
InvHpiDataUpdater updater(info); // good MEG channels, their sensors and the digitised coil positions
updater.prepareDataAndProjectors(segment, MatrixXd::Identity(info->nchan, info->nchan));
// The coil frequencies are known but not their order; the first fit with bOrderFrequencies finds it.
const InvHpiModelParameters model(QVector<int>({154, 158, 161, 166}), info->sfreq, info->linefreq, true);
InvHpiFit hpi(updater.getSensors());
HpiFitResult fit;
hpi.fit(updater.getProjectedData(), updater.getProjectors(), model, updater.getHpiDigitizer(), true, fit);
// MaxFilter head position at t = 0: translation (-0.814, -11.046, 53.572) mm. One 200 ms window, so allow 1 mm
// (test_hpiFit_integration holds the mean over the whole recording to 0.3 mm).
MatrixXd maxfilter;
IOUtils::read_eigen_matrix(maxfilter, data + "/Result/ref_hpiFit_pos.txt");
const Vector3d translation = fit.devHeadTrans.trans.block<3, 1>(0, 3).cast<double>();
const Vector3d reference = maxfilter.block<1, 3>(0, 4).transpose();

ex_dsp_rt​

DSP real-time workers: averaging, covariance, noise spectrum, connectivity, HPI fitting and inverse operators.

src/examples/ex_dsp_rt/main.cpp, line 290
InvHpiDataUpdater updater(hpiInfo); // MEG picks, sensor geometry and digitised coil positions
updater.prepareDataAndProjectors(hpiData, projectors);
const InvHpiModelParameters model(QVector<int>({166, 154, 161, 158}), hpiInfo->sfreq, hpiInfo->linefreq, false);

ex_hpiFit​

Example for cHPI fitting on raw data with SSP. The result is written to a .txt file for comparison with MaxFilter's .pos file.

src/examples/ex_hpiFit/main.cpp, line 182
InvHpiDataUpdater hpiDataUpdater = InvHpiDataUpdater(pFiffInfo);
InvHpiFit HPI = InvHpiFit(hpiDataUpdater.getSensors());

Authors of this file​