cwt: Continuous Wavelet Transform (CWT)

In MassSpecWavelet: Mass spectrum processing by wavelet-based algorithms

Description

CWT(Continuous Wavelet Transform) with Mexican Hat wavelet (by default) to match the peaks in Mass Spectrometry spectrum

Usage

cwt(ms, scales = 1, wavelet = "mexh")

Arguments

ms	Mass Spectrometry spectrum (a vector of MS intensities)
scales	a vector represents the scales at which to perform CWT.
wavelet	The wavelet base, Mexican Hat by default. User can provide wavelet Psi(x) as a form of two row matrix. The first row is the x value, and the second row is Psi(x) corresponding to x.

Value

The return is the 2-D CWT coefficient matrix, with column names as the scale. Each column is the CWT coefficients at that scale.

Author(s)

Pan Du, Simon Lin

Examples

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

	## Plot the 2-D CWT coefficients as image (It may take a while!)
	xTickInterval <- 1000
	image(5000:11000, scales, wCoefs, col=terrain.colors(256), axes=FALSE, xlab='m/z index', ylab='CWT coefficient scale', main='CWT coefficients')
	axis(1, at=seq(5000, 11000, by=xTickInterval))
	axis(2, at=c(1, seq(10, 64, by=10)))
	box()

Example output

Loading required package: waveslim

waveslim: Wavelet Method for 1/2/3D Signals (version = 1.7.5)

MassSpecWavelet documentation built on Nov. 8, 2020, 5:36 p.m.