topoCoord: Compute projections for plotting scalp topographies

In tdeenes/eegR: Analyze EEG Signals

Description

topoCoord computes the topographic projection of the amplitudes at the given peaks.

Usage

topoCoord(
  dat,
  peak_df,
  ch_pos,
  size_x,
  size_y,
  shift_y,
  r = 1,
  ampl_range = NULL,
  resol = 50L,
  resolcol = 101L,
  projection = "laea",
  projref = c("pole", "equator"),
  origo = c(lat = ifelse(projref == "pole", 90, 0), long = ifelse(projref == "pole",
    270, 0)),
  ...
)

Arguments

dat	array of ERP data
peak_df	data.frame of peaks (time and potentially other facetting variables)
ch_pos	data.frame of channel positions
size_x	the width of the topoplot in time units
size_y	the height of the topoplot in amplitude units
shift_y	the vertical center of the topoplot in amplitude units
r	radius of the channel positions if ch_pos does not contain it (default: 1)
ampl_range	numeric vector of length 2 containing the minimum and maximum values. If NULL, it is computed from the data. Values outside the ampl_range interval are set equal to the corresponding limit.
resol	an integer value; the resolution of the grid topographic map in horizontal and vertical direction (default: 30)
resolcol	integer value, the number of levels (resolution) for colouring (default: 101L)
projection	character value (default = "laea"). See http://www.remotesensing.org/geotiff/proj_list/ for common projections.
projref	projection reference (pole [default] or equator)
origo	a named character vector of lat and long coordinates of the origo
...	arguments passed to chanInterp. You might consider setting the argument N for dense electrode caps.

Value

The function returns a named list of two data.table objects (topo and boundary).

Note

This function is called by plotButterfly and plotMap.

tdeenes/eegR documentation built on April 19, 2021, 4:17 p.m.