csd.h File Reference

Cross-spectral density (CSD) estimation via averaged windowed FFTs. More...

#include "dsp_global.h"
#include <Eigen/Core>
#include <Eigen/Dense>
#include <QVector>

Include dependency graph for csd.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Classes
struct	UTILSLIB::CsdResult
	Result of a Cross-Spectral Density computation. More...
class	UTILSLIB::Csd
	Cross-Spectral Density (CSD) estimator. More...

Namespaces
namespace	UTILSLIB
	Shared utilities (I/O helpers, spectral analysis, layout management, warp algorithms).

Detailed Description

Cross-spectral density (CSD) estimation via averaged windowed FFTs.

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

Author

Christoph Dinh chris.nosp@m.toph.nosp@m..dinh.nosp@m.@mne.nosp@m.-cpp..nosp@m.org

Since

2.2.0

Date

April 2026

The cross-spectral density matrix is the frequency-domain counterpart of the time-domain covariance and the central quantity behind coherence, phase-locking value and weighted phase-lag index connectivity measures. For each requested frequency the estimator computes the average outer product X(f) · X(f)ᴴ of the complex Fourier coefficients across windowed segments (and, optionally, across multitaper eigenspectra), yielding the (n_channels × n_channels) Hermitian CSD matrix per frequency bin.

Both Welch-style segmenting (overlapping Hann-windowed segments) and multitaper averaging (Slepian / DPSS tapers via Dpss) are supported to trade between spectral leakage, bias and variance. The output is compatible with the connectivity routines in CONNECTIVITYLIB.

Definition in file csd.h.