cwt {MassSpecWavelet} | R Documentation

## Continuous Wavelet Transform (CWT)

### 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()

[Package MassSpecWavelet version 1.2.0 Index]