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Xdawn

Namespace: RTPROCESSINGLIB  ·  Library: DSP Library

Python equivalent

mne.preprocessing.Xdawn in MNE-Python.

#include <dsp/xdawn.h>

class UTILSLIB::Xdawn

Event-related response enhancement with xDAWN spatial filtering.

Typical usage:

auto xd = Xdawn::fit(epochs, 1, 4);
Eigen::MatrixXd comp = Xdawn::apply(epoch.epoch, xd);      // 4 x n_samples
Eigen::MatrixXd den  = Xdawn::denoise(epoch.epoch, xd, 2); // n_channels x n_samples

Static Methods​

fit(epochs, iTargetEvent, nComponents, dReg)​

Fit xDAWN spatial filters for a target event code.

Uses non-rejected epochs only. The target signal covariance is estimated from the average of epochs whose MNEEpochData::event equals iTargetEvent. The noise covariance is estimated from residuals around the class-wise average for each event type.

Parameters:

  • epochs : const QVector< MNEEpochData > & Input epochs.

  • iTargetEvent : int Event code whose ERP/ERF should be enhanced.

  • nComponents : int Number of xDAWN components to retain.

  • dReg : double Relative diagonal regularisation added to the noise covariance.

Returns:

  • XdawnResult — XdawnResult containing filters, patterns, and covariances.

apply(matEpoch, result)​

Project one epoch into xDAWN component space.

Parameters:

  • matEpoch : const Eigen::MatrixXd & Epoch data (n_channels x n_samples).

  • result : const XdawnResult & Result from fit().

Returns:

  • Eigen::MatrixXd — Component activations (n_components x n_samples).

denoise(matEpoch, result, nComponents)​

Reconstruct one epoch from the first nComponents xDAWN components.

If nComponents <= 0 or exceeds the fitted dimensionality, all fitted components are used.

Parameters:

  • matEpoch : const Eigen::MatrixXd & Epoch data (n_channels x n_samples).

  • result : const XdawnResult & Result from fit().

  • nComponents : int Number of leading xDAWN components to keep.

Returns:

  • Eigen::MatrixXd — Denoised epoch (n_channels x n_samples).

denoiseEpochs(epochs, result, nComponents)​

Apply denoise() to all epochs in the vector, preserving metadata.

Parameters:

  • epochs : const QVector< MNEEpochData > & Input epochs.

  • result : const XdawnResult & Result from fit().

  • nComponents : int Number of leading xDAWN components to keep.

Returns:

  • QVector< MNEEpochData > — Copy of the input epochs with denoised epoch matrices.

Authors of this file​