Compute cross-spectral density

Calculates the cross-spectral density between channel pairs.

Usage

crossSpectrum(
  x,
  channels = NULL,
  nperseg = 256L,
  noverlap = NULL,
  assay_name = NULL
)

Arguments

x

A PhysioExperiment object.

channels

Integer vector of channel indices. If NULL, uses all.

nperseg

Number of samples per segment. Default is 256.

noverlap

Number of overlapping samples.

assay_name

Input assay name.

Value

A list with the following components:

csd

3D complex array of cross-spectral density values (frequency x channel x channel)

frequencies

Numeric vector of frequencies in Hz

channel_names

Character vector of channel names

References

Oppenheim, A.V. & Willsky, A.S. (1997). "Signals and Systems." 2nd ed. Prentice Hall.

See also

coherence() for magnitude-squared coherence, connectivityMatrix() for a unified connectivity interface, spectrogram() for single-channel spectral analysis.

Examples

set.seed(123)
pe <- PhysioExperiment(
  assays = list(raw = matrix(rnorm(2000), nrow = 500, ncol = 4)),
  samplingRate = 256
)

# Compute cross-spectral density
csd <- crossSpectrum(pe)