correlation.h File Reference

Pearson correlation coefficient between every pair of zero-lag time-domain channels. More...

#include "../connectivity_global.h"
#include "abstractmetric.h"
#include "../connectivitysettings.h"
#include <QSharedPointer>
#include <Eigen/Core>

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Classes
class	CONNECTIVITYLIB::Correlation
	Pearson correlation estimator; broadband, zero-lag time-domain baseline. More...

Namespaces
namespace	CONNECTIVITYLIB
	Functional connectivity metrics (coherence, PLV, cross-correlation, etc.).

Detailed Description

Pearson correlation coefficient between every pair of zero-lag time-domain channels.

SPDX-License-Identifier: BSD-3-Clause Copyright (c) 2018-2026 MNE-CPP Authors

Author

Lorenz Esch loren.nosp@m.z.es.nosp@m.ch@tu.nosp@m.-ilm.nosp@m.enau..nosp@m.de; Juan GPC jgarc.nosp@m.iapr.nosp@m.ieto@.nosp@m.mgh..nosp@m.harva.nosp@m.rd.e.nosp@m.du; Gabriel Motta gabri.nosp@m.elbe.nosp@m.nmott.nosp@m.a@gm.nosp@m.ail.c.nosp@m.om; Christoph Dinh chris.nosp@m.toph.nosp@m..dinh.nosp@m.@mne.nosp@m.-cpp..nosp@m.org

Since

0.1.0

Date

January 2018

For two zero-mean, unit-variance signals x[t] and y[t] this is simply

r_{xy} = E[ x[t] * y[t] ]

with output in [-1, 1] - the time-domain, broadband, zero-lag counterpart of magnitude-squared coherence. It is the simplest possible functional-connectivity measure and is included here as a baseline: it carries no spectral information, has no rejection of volume-conduction / common-reference mixing, and is dominated by whichever frequency band has the largest amplitude in the broadband signal. For lag-resolved or band-limited interactions use CrossCorrelation, Coherence or one of the phase-based estimators.

Trials are processed in parallel through QtConcurrent::mappedReduced; the per-trial correlation matrices are summed in reduce and divided by the number of trials at the end to obtain the trial-averaged result.

Definition in file correlation.h.