topo.scalp: plot ERP waveforms in a scalp array with topographic position
In erpR: Event-Related Potentials (ERP) Analysis, Graphics and Utility Functions

Description Usage Arguments Details Value Note Author(s) See Also Examples

This function plots the waveforms of several electrodes in a topographic array reflecting their positions on the scalp

topo.scalp(erpdfs, smo=NULL, ylims="auto", yrev=TRUE, 
startmsec=NULL, endmsec=NULL, lwd=1, lty=1, 
color.list=c("blue", "red", "darkgreen"), legend=F, legend.lab="default", 
t.axis=NULL, elec.coord=NULL, el.toplot=NULL, x.margin=1, y.margin=1, ...)

`erpdfs`	a list indicating the ERP data frame to be plotted. All electrodes specified in the parameter `layout` will be plotted. The other electrodes will be ignored.
`smo`	the smoothing parameter to apply (see `smooth.spline`). Default is `NULL` and no smoothing is applied.
`ylims`	a number indicating the upper and lower limits of the y-axis. If "auto", the function calculates the y limits automatically.
`yrev`	logical. If `TRUE`, the y-axis is plotted with the negative values upward.
`startmsec`	the start time (in ms) of the erpdfs.
`endmsec`	the end time (in ms) of the ERP erpdfs.
`lwd`	a vector specifying the line width to be associated with each ERP data frame specified in `categ`
`lty`	a vector specifying the line types to be associated with each ERP data frame specified in `categ`
`color.list`	a vector specifying the colors to be associated with each ERP data frame specified in `categ`
`legend`	logical. If `TRUE` a legend with object names is drawn in the top-right corner of the array (currently not supported).
`legend.lab`	the legend labels. If "default", the names are retrieved from `erpdf` (currently not supported).
`t.axis`	the position of the ticks on an additional axis indicating the time. This axis is plotted in the bottom-left corner of the plot array. Default is from startmsec to endmsec with steps of 200 ms.
`elec.coord`	The coordinates of electrodes to be plotted. If `NULL` (the default), the electrode positions are retrieved from `topoplot` function.
`el.toplot`	A vector with the names of the electrodes to be plotted.
`x.margin`	A parameter to set the size of xlim in the plot. Default is 1 and larger values make a bigger plot on x-axis.
`y.margin`	A parameter to set the size of xlim in the plot. Default is 1 and larger values make a bigger plot on y-axis.
`...`	Further parameters to be passed to the `erp` function, called within `topo.scalp`

Electrode position are by default retrieved from topoplot, function (see topoplot for details on how to supply other electrode locations). Electrodes are plotted on a 2D surface using the equalarea projection.

The function plots a map of ERP waveforms in an array reflecting the topographic locations of the electrodes on the scalp.

Currently this function supports a limited number of electrode locations. Some electrodes may not be shown because of this limitation.

Giorgio Arcara

topoplot

data(erplistExample)

word=grandaverage("Exp1_word_subj", 1:20, erplist=erplistExample)

nonword=grandaverage("Exp1_nonword_subj", 1:20, erplist=erplistExample)

topo.scalp(list(word), layout=1, ylim=10)

topo.scalp(list(word, nonword), layout=1, ylim=10, legend=TRUE)