Robust Estimators for Multi-Group and Spatial Data R package ssMRCD version 2.0.1 Estimation of robust estimators for multi-group and spatial data including the casewise robust Spatially Smoothed Minimum Regularized Determinant (ssMRCD) estimator and its usage for local outlier detection as described in Puchhammer and Filzmoser (2023) <doi:10.1080/10618600.2023.2277875> as well as for sparse robust PCA for multi-source data described in Puchhammer, Wilms and Filzmoser (2024) <doi:10.48550/arXiv.2407.16299>. Moreover, a cellwise robust multi-group Gaussian mixture model (MG-GMM) is implemented as described in Puchhammer, Wilms and Filzmoser (2024) <doi:10.48550/arXiv.2504.02547>. Included are also complementary visualization and parameter tuning tools. Software Depends: R (>= 4.0.0) Imports: stats, graphics, robustbase, scales, ellipse, dbscan, ggplot2, expm, rrcov, DescTools, rootSolve, Matrix, Rcpp, RcppArmadillo, cellWise, methods, utils LinkingTo: Rcpp, RcppArmadillo Suggests: knitr, rmarkdown, testthat (>= 3.0.0), rnaturalearth, rnaturalearthdata, dplyr, tidyr, ggridges Patricia Puchhammer <patricia.puchhammer@tuwien.ac.at> Comprehensive R Archive Network (CRAN) Patricia Puchhammer [aut, cre, cph], Peter Filzmoser [aut] GPL-3 2025-09-16 application/tgz https://CRAN.R-project.org/package=ssMRCD doi:10.32614/CRAN.package.ssMRCD