Plot EEG Butterfly Traces with Global Field Power

Displays the selected continuous EEG channels as a butterfly plot above their Global Field Power (GFP). GFP is the spatial dispersion across the displayed channels at each time point, so its magnitude depends on the selected channels and EEG reference. It is not source-localized power.

Usage

eegPlotButterflyGFP(
  x,
  channels = NULL,
  time_range = NULL,
  show_events = FALSE,
  assay_name = NULL,
  gfp_definition = c("population", "sample"),
  heights = c(3, 1)
)

Arguments

x

A PhysioExperiment object containing a numeric 2D continuous EEG assay (time x channels).

channels

Unique character vector of exact channel labels. If NULL, all channels are shown.

time_range

Optional finite increasing length-two vector specifying the inclusive display range in seconds. GFP is calculated before display windowing.

show_events

Logical; draw finite event times from metadata(x)$events on both panels.

assay_name

Input assay name. If NULL, uses the default assay.

gfp_definition

Denominator used for spatial dispersion: "population" divides by C and matches eegMicrostates(); "sample" divides by C - 1.

heights

Two finite positive values giving the butterfly and GFP panel height ratio.

Value

A patchwork object containing two ggplot panels.

Examples

if (FALSE) { # \dontrun{
pe <- make_eeg(n_time = 2500, n_channels = 8, sr = 500)
eegPlotButterflyGFP(pe, channels = c("Fz", "Cz", "Pz"))
} # }