peaks_find {gamma}R Documentation

Find Peaks

Description

Finds local maxima in sequential data.

Usage

peaks_find(object, ...)

## S4 method for signature 'GammaSpectrum'
peaks_find(object, method = c("MAD"), SNR = 2, span = NULL, ...)

Arguments

object

A GammaSpectrum object.

...

Extra parameters to be passed to internal methods.

method

A character string specifying the method to be used for background noise estimation (see below).

SNR

An integer giving the signal-to-noise-ratio for peak detection (see below).

span

An integer giving the half window size (in number of channels). If NULL, 5\ window size.

Details

A local maximum has to be the highest one in the given window and has to be higher than SNR×noiseSNR \times noise to be recognized as peak.

The following methods are available for noise estimation:

MAD

Median Absolute Deviation.

Value

A PeakPosition object.

Author(s)

N. Frerebeau

See Also

Other signal processing: baseline, peaks_search(), signal_integrate(), signal_slice(), signal_split(), signal_stabilize(), smooth()

Examples

## Import a LaBr spectrum
LaBr_file <- system.file("extdata/LaBr.TKA", package = "gamma")
LaBr_spc <- read(LaBr_file)

## Find peaks by channel
(LaBr_pks <- peaks_find(LaBr_spc)) # Ugly
plot(LaBr_spc, LaBr_pks)

## Search peaks by channel
(LaBr_pks <- peaks_search(LaBr_spc, index = c(86L, 207L, 496L), span = 7))
plot(LaBr_spc, LaBr_pks, split = TRUE)

## Import a BEGe spectrum
BEGe_file <- system.file("extdata/BEGe.CNF", package = "gamma")
BEGe_spc <- read(BEGe_file)

## Search peaks by energy
(BEGe_pks <- peaks_search(BEGe_spc, index = c(47, 63, 911, 1460)))
plot(BEGe_spc, BEGe_pks, split = TRUE)

[Package gamma version 1.0.5 Index]