# localmax: calculate a local maximum In erpR: Event-Related Potentials (ERP) Analysis, Graphics and Utility Functions

## Description

The function calculates a local maximum of the vector `x` surrounded by at least `n.points` lower numbers.

## Usage

 `1` ```localmax(x, n.points=2) ```

## Arguments

 `x` a vector of numbers. `n.points` a minimum number of lower values to determine the local maximum. Default is two points.

## Details

The function calculates a local maximum of the vector `x`, i.e. the highest value of the vector `x` surrounded by at least `n` lower numbers. The concept of the local maximum applied to ERP analysis is taken from Luck (2005).

## Value

The local maximum of the vector `x` is returned.

Giorgio Arcara

## References

Luck, S., J. (2005). An Introduction to the Event-Related Potential Technique. Cambridge, Mass.: The MIT Press.

## Examples

 ```1 2 3 4 5 6 7 8``` ```x=seq(-5.5,1,0.001) y=sin(x)+0.3*x plot(x,y, type="l") #print an horizontal line intersecting the local maximum abline(h=localmax(y)) ```

erpR documentation built on July 31, 2018, 3 p.m.