eegtime: Plots Single-Channel EEG Time Course

In eegkit: Toolkit for Electroencephalography Data

Description

Creates plot of single-channel electroencephalography (EEG) time course with optional confidence interval. User can control the plot orientation, line types, line colors, etc.

Usage

eegtime(time, voltage, flipvoltage = TRUE, vlty = 1, vlwd = 2,
        vcol = "blue", voltageSE = NULL, slty = NA, slwd = 1,
        scol = "cyan", salpha = 0.65, conflevel = 0.95,
        plotzero = TRUE, zlty = 1, zlwd = 0.5, zcol = "black",
        xlim = NULL, ylim = NULL, xlab = NULL, ylab = NULL,
        nxtick = 6, nytick = 6, xticks = NULL, yticks = NULL,
        add = FALSE, ...)

Arguments

time	Vector of time points at which EEG was recorded.
voltage	Vector of recorded EEG voltage at each point in time.
flipvoltage	If TRUE, negative voltages are plotted upwards.
vlty	Line type for voltage.
vlwd	Line width for voltage.
vcol	Line color for voltage.
voltageSE	Vector of standard errors of EEG voltage at each point in time.
slty	Line type for voltageSE. If slty=NA (default) shaded polygons are plotted.
slwd	Line width for voltageSE. Ignored if slty=NA.
scol	Polygon or line color for voltageSE.
salpha	Transparency value for voltageSE polygon (only used if slty=NA).
conflevel	Confidence level to use for confidence intervals. Default forms 95% CI.
plotzero	If TRUE, horizontal reference line is plotted at 0 volts.
zlty	Line type for reference line. Ignored if plotzero=FALSE.
zlwd	Line width for reference line. Ignored if plotzero=FALSE.
zcol	Line color for reference line. Ignored if plotzero=FALSE.
xlim	Plot limits for time.
ylim	Plot limits for voltage.
xlab	Plot label for time.
ylab	Plot label for voltage.
nxtick	Approximate number of axis ticks for time.
nytick	Approximate number of axis ticks voltage.
xticks	x-axis ticks for time (overrides nxtick).
yticks	y-axis ticks voltage (overrides nytick).
add	If TRUE, lines are added to current plot; otherwise a new plot is created.
...	Optional inputs for plot or lines function.

Value

Produces plot of EEG time course with NULL return value.

Note

Confidence intervals are formed using the normal (Gaussian) distribution.

Author(s)

Nathaniel E. Helwig <[e-mail]>

References

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.

Examples

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

# get "PZ" electrode from "eegdata" data
data(eegdata)
idx <- which(eegdata$channel=="PZ")
eegdata <- eegdata[idx,]

# get average and standard error (note se=sd/sqrt(n))
eegmean <- tapply(eegdata$voltage,list(eegdata$time,eegdata$group),mean)
eegse <- tapply(eegdata$voltage,list(eegdata$time,eegdata$group),sd)/sqrt(50) 

# plot results with legend
tseq <- seq(0,1000,length.out=256)
eegtime(tseq,eegmean[,2],voltageSE=eegse[,2],ylim=c(-10,6),main="Pz")
eegtime(tseq,eegmean[,1],vlty=2,vcol="red",voltageSE=eegse[,1],scol="pink",add=TRUE)
legend("bottomright",c("controls","alcoholics"),lty=c(1,2),
       lwd=c(2,2),col=c("blue","red"),bty="n")

eegkit documentation built on May 1, 2019, 8:02 p.m.