direct_osc: Direct Orthogonal Signal Correction

In ChristianGoueguel/specProc: Preprocessing Tools For Laser-Induced Breakdown Spectroscopy (LIBS) Spectra

Direct Orthogonal Signal Correction

Description

This function implements the Direct Orthogonal Signal Correction (DOSC) algorithm, as proposed by Westerhuis et al. (2001), to remove systematic variation from predictor variables, \textbf{X}, that is orthogonal to the response variable(s), \textbf{Y}.

Usage

direct_osc(
  x,
  y,
  ncomp = 10,
  center = TRUE,
  scale = FALSE,
  tol = 0.001,
  max_iter = 10
)

Arguments

x	A matrix or data frame of the predictor variables
y	A vector, matrix or data frame of the response variable(s)
ncomp	An integer specifying the number of principal components to retain for orthogonal processing. Default is 10.
center	A logical value specifying whether to center the data. Default is TRUE.
scale	A logical value specifying whether to scale the data. Default is FALSE.
tol	A numeric value representing the tolerance for convergence. The default value is 1e-3.
max_iter	An integer representing the maximum number of iterations. The default value is 10.

Details

Different from the Orthogonal Signal Correction (OSC) algorithm, Wold et al. (1998), the DOSC algorithm firstly orthogonalizes the matrices \textbf{X} and \textbf{Y}. Then principal components analysis (PCA) is performed on the orthogonalized \textbf{X} to obtain the scores \textbf{T} and loadings \textbf{P} matrices.

Value

A list with the following components:

• correction: The corrected matrix.

• loading: The loadings matrix.

• score: The scores matrix.

Author(s)

Christian L. Goueguel

References

• Westerhuis, J.A., Jong, S.D., Smilde, A.K., (2001). Direct orthogonal signal correction. Chemometrics Intell. Lab. Syst., 56(1):13-25

• Wold, S., Antti, H., Lindgren, F., Ohman, J. (1998). Orthogonal signal correction of near-infrared spectra. Chemometrics Intell. Lab. Syst., 44(1):175-185.

ChristianGoueguel/specProc documentation built on Nov. 9, 2024, 3:23 p.m.