Block Structure Detection Using Singular Vectors R package bdsvd version 1.2.1 Provides methods to perform block diagonal covariance matrix detection using singular vectors ('BD-SVD'), which can be extended to inherently sparse principal component analysis ('IS-PCA'). The methods are described in Bauer (2025) <doi:10.1080/10618600.2024.2422985> and Bauer (2026) <doi:10.48550/arXiv.2510.03729>. Software Imports: irlba, matrixStats, Rcpp, stats LinkingTo: Rcpp, RcppArmadillo Suggests: cvCovEst, glasso, mvtnorm, dslabs, testthat (>= 3.0.0) Jan O. Bauer <j.bauer@vu.nl> Comprehensive R Archive Network (CRAN) Jan O. Bauer [aut, cre] (ORCID: <https://orcid.org/0000-0001-7123-4507>), Ron Holzapfel [aut] GPL (>= 2) 2026-03-26 application/tgz https://CRAN.R-project.org/package=bdsvd doi:10.32614/CRAN.package.bdsvd