Generic coupling matrix across channel pairs

Computes any coupling method for all pairs of channels between two sets of signals, extracting a scalar statistic for each pair. This is the multi-channel generalisation of couplingAnalysis.

Usage

couplingMatrix(
  x,
  y = NULL,
  sr = NULL,
  method,
  channels_x = NULL,
  channels_y = NULL,
  modality_x = NULL,
  modality_y = NULL,
  ...
)

Arguments

x

A PhysioExperiment or MultiPhysioExperiment object.

y

A PhysioExperiment, or NULL when x is an MPE.

sr

Numeric sampling rate in Hz.

method

Character coupling method, one of "coherence", "plv", "pli", "wpli", "granger", "crosscorrelation".

channels_x, channels_y

Integer vectors of channel indices, or NULL for all channels.

modality_x, modality_y

Character modality names for MPE input.

...

Additional arguments passed to the coupling function.

Value

A list with components:

matrix

Numeric matrix of coupling values.

method

Character method used.

channel_names_x

Character vector of x channel names.

channel_names_y

Character vector of y channel names.

References

Carter, G. C. (1987). Coherence and time delay estimation. Proceedings of the IEEE, 75(2), 236–255.

See also

couplingAnalysis(), coherenceMatrix(), plotCouplingMatrix(), surrogateMatrixTest()

Examples

sr <- 200; n <- sr * 2
pe1 <- PhysioExperiment(
  assays = list(raw = matrix(rnorm(n * 2), nrow = n)),
  samplingRate = sr
)
pe2 <- PhysioExperiment(
  assays = list(raw = matrix(rnorm(n * 2), nrow = n)),
  samplingRate = sr
)
result <- couplingMatrix(pe1, pe2, method = "coherence", nperseg = 64L)
result$matrix
#>           y_ch1     y_ch2
#> x_ch1 0.2266249 0.3193599
#> x_ch2 0.2407800 0.2505534