getLocalMaximumCWT: Identify the local maximum of each column in 2-D CWT...

In zeehio/MassSpecWavelet: Peak Detection for Mass Spectrometry data using wavelet-based algorithms

Identify the local maximum of each column in 2-D CWT coefficients matrix

Description

Identify the local maximum of each column in 2-D CWT coefficients matrix by using a slide window. The size of slide window linearly changes from the coarse scale (bigger window size) to detail scale. The scale of CWT increases with the column index.

Usage

getLocalMaximumCWT(
  wCoefs,
  minWinSize = 5,
  amp.Th = 0,
  isAmpThreshRelative = FALSE,
  exclude0scaleAmpThresh = FALSE
)

Arguments

wCoefs	2-D CWT coefficients, each column corresponding to CWT coefficient at one scale. The column name is the scale.
minWinSize	The minimum slide window size used.
amp.Th	The minimum peak amplitude.
isAmpThreshRelative	Whether amp.Th is given relative to max(wCoefs).
exclude0scaleAmpThresh	When computing the relative amp.Th, if this is set to TRUE, the amp.Th will exclude the zero-th scale from the max(wCoefs). The zero-th scale corresponds to the original signal, that may have a much larger baseline than the wavelet coefficients and can distort the threshold calculation. The default is FALSE to preserve backwards compatibility.

Value

return a matrix with same dimension as CWT coefficient matrix, wCoefs. The local maxima are marked as 1, others are 0.

Author(s)

Pan Du

See Also

localMaximum()

Examples

data(exampleMS)
scales <- seq(1, 64, 3)
wCoefs <- cwt(exampleMS[5000:11000], scales = scales, wavelet = "mexh")

localMax <- getLocalMaximumCWT(wCoefs)
plotLocalMax(localMax)

zeehio/MassSpecWavelet documentation built on May 6, 2023, 1:32 a.m.