Spatial Distribution Dynamics R package sddr version 0.1.1 A tidy toolkit for distribution dynamics: analysing how a cross-sectional distribution of values evolves over time and where it settles in the long run. Provides discrete-time, spatial, rank and local indicator of spatial association ('LISA') Markov transition estimation, ergodic analysis (steady-state, mean first passage and sojourn times), rank-mobility measures (Kendall's tau and the Theta statistic) and Markov mobility indices. Methods use long-format 'id'/'time'/'value' data rather than transition matrices and build on the distribution-dynamics literature (Quah (1993); Rey (2001) <doi:10.1111/j.1538-4632.2001.tb00444.x>). Results are validated for numerical parity against the reference 'giddy' library. Software Imports: stats Suggests: reticulate, spdep, testthat (>= 3.0.0) Muhammad Farooqi <mqfarooqi@gmail.com> Comprehensive R Archive Network (CRAN) Muhammad Farooqi [aut, cre] (ORCID: <https://orcid.org/0000-0003-4918-9791>) MIT + file LICENSE (https://CRAN.R-project.org/package=sddr/LICENSE) 2026-07-19 application/tgz https://CRAN.R-project.org/package=sddr doi:10.32614/CRAN.package.sddr