MLSP: Machine Learning Models for Soil Properties from Spectroscopy

Soil spectroscopy studies use many different combinations of spectral preprocessing and calibration methods, which makes results difficult to compare or generalize across studies. For visible and near-infrared (VNIR) spectra (350-2500 nm), runs every combination of preprocessing and calibration methods on identical repeated calibration and validation splits. The 26 preprocessing methods are raw reflectance, standard normal variate, pseudo-absorbance, and 23 Savitzky-Golay smoothers, first derivatives, and second derivatives with linear, quadratic, or cubic polynomials and 3- to 11-point windows, excluding settings that give mathematically identical filters. The calibration methods are principal component regression (PCR), partial least squares regression (PLSR), least absolute shrinkage and selection operator (LASSO), 'Cubist', and random forest. Model complexity is tuned by cross-validation within each calibration set, and combinations are ranked by the coefficient of determination (R2), root mean squared error (RMSE), ratio of performance to interquartile distance (RPIQ), or bias, reporting the top 10 by default. The methods are those most commonly used in published soil spectroscopy studies, following Savitzky and Golay (1964) <doi:10.1021/ac60214a047>, Barnes et al. (1989) <doi:10.1366/0003702894202201>, Rinnan et al. (2009) <doi:10.1016/j.trac.2009.07.007>, Bellon-Maurel et al. (2010) <doi:10.1016/j.trac.2010.05.006>, and Clingensmith et al. (2019) <doi:10.1111/ejss.12753>.

Version: 0.2.0
Imports: stats, utils, gsignal, pls, glmnet, Cubist, randomForest
Suggests: testthat (≥ 3.0.0)
Published: 2026-10-29
DOI: 10.32614/CRAN.package.MLSP
Author: Pengyuan Chen [aut], Christopher Clingensmith [aut], Chenglong Ye [aut], Sabine Grunwald [aut], Katsutoshi Mizuta [aut, cre]
Maintainer: Katsutoshi Mizuta <toshi.m at uky.edu>
License: GPL-2
NeedsCompilation: no
Materials: NEWS
CRAN checks: MLSP results

Documentation:

Reference manual: MLSP.html , MLSP.pdf

Downloads:

Package source: MLSP_0.2.0.tar.gz
Windows binaries: r-devel: MLSP_0.1.0.zip, r-release: MLSP_0.2.0.zip, r-oldrel: MLSP_0.2.0.zip
macOS binaries: r-release (arm64): MLSP_0.2.0.tgz, r-oldrel (arm64): MLSP_0.2.0.tgz, r-release (x86_64): MLSP_0.2.0.tgz, r-oldrel (x86_64): MLSP_0.2.0.tgz
Old sources: MLSP archive

Linking:

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