R Codes for Preprocessing FT-NIR, FTIR, and Raman Spectral Data and Machine Learning Tools for Predictive and Classification Model Calibration

In this work, R codes are provided for the preprocessing of FT-NIR, FTIR, and Raman spectral data to facilitate efficient and reproducible spectral analysis workflows. Baseline correction, smoothing, normalization, and derivative calculations are included in the scripts to prepare the spectral data for subsequent modeling. Additionally, R-based tools and workflows are provided for the application of machine learning techniques, including regression and classification algorithms, to calibrate predictive and classification models using the preprocessed spectral data. These tools are intended to support researchers in the development of robust models for chemical and quality analysis, ensuring transparency and replicability in spectral data processing and machine learning calibration pipelines.