The 'chemometrics' package is an R companion to the book "Introduction to Multivariate Statistical Analysis in Chemometrics" by K. Varmuza and P. Filzmoser (2009). It provides functions for multivariate statistical methods, diagnostics, calibration, cross-validation, bootstrap, clustering, and more. The package includes data sets for various applications, such as glass, ash, cereal, and NIR data, which can be used for analysis and verification of the book's examples. Key functions include `alr` for additive logratio transformation, `clr` for centered logratio transformation, `ilr` for isometric logratio transformation, and `pcaCV` for principal component analysis with cross-validation. The package also supports k-Nearest Neighbors (kNN) classification, Lasso regression, and partial robust M-regression, among other statistical techniques.The 'chemometrics' package is an R companion to the book "Introduction to Multivariate Statistical Analysis in Chemometrics" by K. Varmuza and P. Filzmoser (2009). It provides functions for multivariate statistical methods, diagnostics, calibration, cross-validation, bootstrap, clustering, and more. The package includes data sets for various applications, such as glass, ash, cereal, and NIR data, which can be used for analysis and verification of the book's examples. Key functions include `alr` for additive logratio transformation, `clr` for centered logratio transformation, `ilr` for isometric logratio transformation, and `pcaCV` for principal component analysis with cross-validation. The package also supports k-Nearest Neighbors (kNN) classification, Lasso regression, and partial robust M-regression, among other statistical techniques.