grandaverage: calculate the grandaverage of ERP data frames for graphical...
In erpR: Event-Related Potentials (ERP) Analysis, Graphics and Utility Functions

Description Usage Arguments Value Note Author(s) Examples

A function to average ERP objects, i.e. data frames with timepoints in rows, electrodes in columns and amplitude values in each cell. It is used to compute the grandaverage across several subjects, for plotting purposes.

1 2	grandaverage(base, numbers, electrodes="all", erplist = NULL, startmsec=NULL, endmsec=NULL, NA.sub=TRUE)

`base`	a string indicating the beginning of the name of the `data.frame` containing the ERP data.
`numbers`	the numbers of subjects to be averaged.
`electrodes`	a character vector indicating the electrodes on which perform the grandaverage. Default is `"all"`, and the `grandaverage` is performed on all electrodes of the data frames.
`startmsec`	the start time (in ms) of the `erpdf`.
`endmsec`	the end time (in ms) of the `erpdf`.
`erplist`	a list containing ERP data frames.
`NA.sub`	logical. If `TRUE`, electrodes columns with `NA` are ignored in grandaverage computation. In this case, a Warning is displayed.

A data frame with the values of subjects specified by the combination of base and numbers.

The function keeps track of the averaged objects in a comment.

Giorgio Arcara

data(erplistExample)
# compute the average of subjects 1 to 20 for the condition 
# specified by the string "Exp1_word_subj".
	
word=grandaverage("Exp1_word_subj", 1:20, erplist=erplistExample)