eegspace: Plots Multi-Channel EEG Spatial Map
In eegkit: Toolkit for Electroencephalography Data

Description Usage Arguments Value Note Author(s) References Examples

Creates plot of multi-channel electroencephalography (EEG) spatial map. User can control the plot type (2d or 3d), the colormap, color, etc.

eegspace(space, voltage, vlim = NULL, mycolors = NULL, ncolor = 25,
         colorbar = TRUE, nctick = 5, rtick = 1, cex.axis = 1,
         barloc = NULL, colorlab = NULL, colorlabline = 3, cex.lab = 1,
         plotaxes = FALSE, main = "", xyzlab = NULL, cex.point = 1,
         cex.main = 1, nose = TRUE, ears = TRUE, head = TRUE,
         col.head = "AntiqueWhite", mar = NULL, ...)

`space`	Matrix of input electrode coordinates (3d or 2d).
`voltage`	Vector of recorded EEG voltage at each row in `space`.
`vlim`	Two-element vector giving the limits to use when mapping `voltage` to colors in `mycolors`. Default is `vlim=range(voltage)`.
`mycolors`	Character vector of colors to use for color mapping (such that `length(mycolors)<=ncolor`). Default: `mycolors=c("blueviolet","blue","cyan","green","yellow","orange","red")`.
`ncolor`	Number of colors to use in mapping (positive integer).
`colorbar`	If `TRUE`, colorbar is plotted.
`nctick`	Approximate number of ticks for colorbar. Ignored if `colorbar=FALSE`.
`rtick`	Round tick labels to given decimal. Ignored if `colorbar=FALSE`.
`cex.axis`	Cex of axis ticks for colorbar. Ignored if `colorbar=FALSE`.
`barloc`	Character vector giving location of color bar. See Notes.
`colorlab`	Character vector giving label for color bar. Ignored if `colorbar=FALSE`.
`colorlabline`	Line number for color bar label (for input to `mtext`).
`cex.lab`	Cex of axis labels for colorbar. Ignored if `colorbar=FALSE`.
`plotaxes`	If `TRUE`, axes labels are plotted. Ignored for 3d plots.
`main`	Plot title. Default is no title.
`xyzlab`	Axis labels to use for plot. If `type="2d"`, then `xyzlab` should be two-element character vector giving x and y axis labels. If `type="3d"`, then `xyzlab` should be three-element character vector giving x, y, and z axis labels.
`cex.point`	Cex for plotted electrodes.
`cex.main`	Cex for plot title. Ignored if `main=NULL`.
`nose`	If `TRUE`, triangle is plotted to represent the subject's nose. Ignored if `ncol(space)==3`.
`ears`	If `TRUE`, ovals are plotted to represent the subject's ears. Ignored if `ncol(space)==3`.
`head`	If `TRUE`, head is plotted. Ignored if `type="2d"`.
`col.head`	Color for dummy head in 3d plot. Ignored if `type="2d"`.
`mar`	Margins to use for plot (see `par`).
`...`	Optional inputs for `plot` or `lines` function.

Produces plot of EEG spatial map with NULL return value.

For 3d plots, barloc can be one of four options: "backright", "backleft", "frontright", or "frontleft". For 2d plots, barloc can be either "right" or "left".

Currently supports spatial maps registered to the 84-channel cap produced by eegcap and eegcoord.

Nathaniel E. Helwig <helwig@umn.edu>

Bache, K. & Lichman, M. (2013). UCI Machine Learning Repository [http://archive.ics.uci.edu/ml]. Irvine, CA: University of California, School of Information and Computer Science.

Begleiter, H. Neurodynamics Laboratory. State University of New York Health Center at Brooklyn. http://www.downstate.edu/hbnl/

Ingber, L. (1997). Statistical mechanics of neocortical interactions: Canonical momenta indicatros of electroencephalography. Physical Review E, 55, 4578-4593.

Ingber, L. (1998). Statistical mechanics of neocortical interactions: Training and testing canonical momenta indicators of EEG. Mathematical Computer Modelling, 27, 33-64.

##########   EXAMPLE   ##########

# get time point 65 (approx 250 ms) from "eegdata" data
data(eegdata)
idx <- which(eegdata$time==65L)
eegdata <- eegdata[idx,]

# get average spatial map
eegmean <- tapply(eegdata$voltage,list(eegdata$channel,eegdata$group),mean)

# remove ears and nose
acnames <- rownames(eegmean)
idx <- c(which(acnames=="X"),which(acnames=="Y"),which(acnames=="nd"),which(acnames=="Cz"))
eegmean <- eegmean[-idx,]

# match to eeg coordinates
data(eegcoord)
cidx <- match(rownames(eegmean),rownames(eegcoord))

# # plot average control voltage in 3d
# open3d()
# eegspace(eegcoord[cidx,1:3],eegmean[,2])

# plot average control voltage in 2d
eegspace(eegcoord[cidx,4:5],eegmean[,2])

# # change 3d bar location and use play3d to rotate (not run)
# open3d()
# par3d(windowRect=c(0,0,600,600))
# eegspace(eegcoord[cidx,1:3],eegmean[,2],barloc="frontleft")
# play3d(spin3d(axis=c(0,0,1),rpm=5),duration=20)

# change 2d bar location
eegspace(eegcoord[cidx,4:5],eegmean[,2],barloc="left")