baseline_rollingball {alkahest} R Documentation

## Rolling Ball Baseline Estimation

### Description

Rolling Ball Baseline Estimation

### Usage

baseline_rollingball(x, y, ...)

## S4 method for signature 'numeric,numeric'
baseline_rollingball(x, y, m, s)

## S4 method for signature 'ANY,missing'
baseline_rollingball(x, m, s)


### Arguments

 x, y A numeric vector. If y is missing, an attempt is made to interpret x in a suitable way (see grDevices::xy.coords()). ... Currently not used. m An odd integer giving the window size (i.e. the number of adjacent points to be used; see window_sliding()) for minimization/maximization. s An odd integer giving the window size (i.e. the number of adjacent points to be used; see window_sliding()) for smoothing.

### Value

Returns a list with two components x and y.

### Note

There will be (m - 1) / 2 points both at the beginning and at the end of the data series for which a complete m-width window cannot be obtained. To prevent data loss, progressively wider/narrower windows are used at both ends of the data series.

N. Frerebeau

### References

Kneen, M. A. and Annegarn, H. J. (1996). Algorithm for Fitting XRF, SEM and PIXE X-Ray Spectra Backgrounds. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 109/110: 209-213. doi:10.1016/0168-583X(95)00908-6.

signal_correct()

Other baseline estimation methods: baseline_linear(), baseline_peakfilling(), baseline_polynomial(), baseline_rubberband(), baseline_snip()

### Examples

## X-ray diffraction
data("XRD")

## Subset from 20 to 70 degrees
XRD <- signal_select(XRD, from = 20, to = 70)

## Plot spectrum
plot(XRD, type = "l", xlab = expression(2*theta), ylab = "Count")

## Rolling Ball baseline
baseline <- baseline_rollingball(XRD, m = 201, s = 151)

plot(XRD, type = "l", xlab = expression(2*theta), ylab = "Count")
lines(baseline, type = "l", col = "red")


[Package alkahest version 1.1.1 Index]