Flexible Integration of Single-Cell RNA-Seq Data R package FIRM version 0.1.2 Provides functions for the flexible integration of heterogeneous scRNA-seq datasets across multiple tissue types, platforms, and experimental batches. Implements the method described in Ming (2022) <doi:10.1093/bib/bbac167>. The package incorporates modified 'C++' source code from the 'flashpca' library (Abraham, 2014-2016 <https://github.com/gabraham/flashpca>) for efficient principal component analysis, and the 'Spectra' library (Qiu, 2016-2025) for large-scale eigenvalue and singular value decomposition; see 'inst/COPYRIGHTS' for details on third-party code. Software Depends: R (>= 3.5.0) Imports: Seurat (>= 5.0.0), RANN LinkingTo: Rcpp, RcppArmadillo, RcppEigen Suggests: ggplot2 Jingsi Ming <jsming@fem.ecnu.edu.cn> Comprehensive R Archive Network (CRAN) Jingsi Ming [aut, cre, cph] (R package development and method implementation, ORCID: 0000-0001-7059-4156), Shuzhen Ding [ctb] (R package development and maintenance), Gad Abraham [ctb, cph] (Original 'flashpca' 'C++' code for fast randomized PCA), Yixuan Qiu [ctb, cph] ('Spectra' library for large-scale eigenvalue and SVD computation), Anna Araslanova [ctb, cph] (Author of 'LOBPCGSolver.h' in 'Spectra'), Felipe Zapata [ctb, cph] (Author of 'DavidsonSymEigsSolver.h' and 'Orthogonalization.h' in 'Spectra' (Netherlands eScience Center)), Nicolas Renaud [ctb, cph] (Author of 'RitzPairs.h' and 'SearchSpace.h' in 'Spectra' (Netherlands eScience Center)), Jens Wehner [ctb, cph] (Author of 'JDSymEigsBase.h' in 'Spectra' (Netherlands eScience Center)), Gael Guennebaud [ctb, cph] ('Eigen' library code for tridiagonal eigenvalue decomposition), Jitse Niesen [ctb, cph] ('Eigen' library code for eigenvalue computation) GPL-3 2026-02-19 application/tgz https://CRAN.R-project.org/package=FIRM doi:10.32614/CRAN.package.FIRM