Tissot Indicatrix for Map Projection Distortion R package tissot version 0.3.0 Compute and visualize the 'Tissot Indicatrix' for map projections. The indicatrix characterizes projection distortion by computing scale factors, angular deformation, areal distortion, and convergence at arbitrary points. Based on the calculations shared by Bill Huber on <https://gis.stackexchange.com/a/5075/482>. Uses 'PROJ' for coordinate transformation and distortion factor computation. Developed using the method published in Snyder, JP (1987) <doi:10.3133/pp1395>. Software Depends: R (>= 3.6.0) Imports: tibble, PROJ, graphics, grDevices, stats Suggests: testthat (>= 3.0.0), knitr, rmarkdown, spelling Michael Sumner <mdsumner@gmail.com> Comprehensive R Archive Network (CRAN) Michael Sumner [aut, cre, cph] (ORCID: <https://orcid.org/0000-0002-2471-7511>), Bill Huber [aut] (original algorithm and calculations) MIT + file LICENSE (https://CRAN.R-project.org/package=tissot/LICENSE) 2026-07-12 application/tgz https://CRAN.R-project.org/package=tissot doi:10.32614/CRAN.package.tissot en-US