soundgen (version 3.0.0)

findPeaks: Find peaks

Description

A bare-bones, very fast function to find local maxima (peaks) in a numeric vector. NAs are set to the minimum value of input and effectively ignored. The first and last values can also be peaks. Plateaus are NOT treated as peaks.

Usage

findPeaks(
  x,
  wl = 3,
  thres = NULL,
  thresRel = NULL,
  dropFirstLast = FALSE,
  plot = FALSE
)

Value

A vector of indices of local maxima.

Arguments

x

numeric vector

wl

rolling window over which we look for maxima: central value ± floor(wl/2), eg ±1 if wl=3; forced to be at least 3

thres

required absolute value of each peak

thresRel

required absolute excess over the window mean excluding the focal point

dropFirstLast

if TRUE, the first and last value cannot be peaks (only two-sided maxima accepted)

plot

if TRUE, plots the input vector with peaks marked.

Examples

x = c(5, 2, 3, 3, 2, 7, 3, 2, 5, 5, 1, 0, 2, NA)
findPeaks(x, wl = 3, plot = TRUE)
findPeaks(x, wl = 3, thres = 2, plot = TRUE)
findPeaks(x, wl = 3, thres = 100, plot = TRUE)
findPeaks(x, wl = 4, plot = TRUE)
findPeaks(x, wl = 6, plot = TRUE)
findPeaks(x, wl = 3, thresRel = 2, plot = TRUE)
findPeaks(x, wl = 3, thresRel = 4, plot = TRUE)
findPeaks(x, wl = 3, thres = 6, thresRel = 2, plot = TRUE)
findPeaks(x, dropFirstLast = TRUE)