baseline: baseline.als – R documentation

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baseline.als

Asymmetric Least Squares

Description

Baseline correction by 2nd derivative constrained weighted regression. Original algorithm proposed by Paul H. C. Eilers and Hans F.M. Boelens

Usage

baseline.als(spectra, lambda = 6, p = 0.05, maxit = 20)

Arguments

`spectra`	Matrix with spectra in rows
`lambda`	2nd derivative constraint
`p`	Weighting of positive residuals
`maxit`	Maximum number of iterations

Details

Iterative algorithm applying 2nd derivative constraints. Weights from previous iteration is p for positive residuals and 1-p for negative residuals.

Value

`baseline`	Matrix of baselines corresponding to spectra `spectra`
`corrected`	Matrix of baseline corrected spectra
`wgts`	Matrix of final regression weights

Author(s)

Kristian Hovde Liland and Bjørn-Helge Mevik

References

Paul H. C. Eilers and Hans F.M. Boelens: Baseline Correction with Asymmetric Least Squares Smoothing

Examples

data(milk)
bc.als <- baseline(milk$spectra[1,, drop=FALSE], lambda=10, method='als')
## Not run: 
plot(bc.als)

## End(Not run)

baseline

Baseline Correction of Spectra

v1.3-1

GPL-2

Authors

Kristian Hovde Liland [aut, cre], Bjørn-Helge Mevik [aut], Roberto Canteri [ctb]

Initial release

2020-09-10