Calculate Slopes of Roads, Rivers and Trajectories R package slopes version 2.0.0 Calculates the slope (longitudinal gradient or steepness) of linear geographic features such as roads (for more details, see Ariza-López et al. (2019) <doi:10.1038/s41597-019-0147-x>) and rivers (for more details, see Cohen et al. (2018) <doi:10.1016/j.jhydrol.2018.06.066>). It can use local Digital Elevation Model (DEM) data or download DEM data via the 'ceramic' package. The package also provides functions to add elevation data to linestrings and visualize elevation profiles. Software Depends: R (>= 2.10) Imports: sf, terra, methods, pbapply, geodist, colorspace Suggests: knitr, rmarkdown, ceramic, bookdown, covr, testthat, osmextract, stplanr, dplyr, tmap, leaflet, bench, rlang Robin Lovelace <rob00x@gmail.com> Comprehensive R Archive Network (CRAN) Robin Lovelace [aut, cre, cph] (ORCID: <https://orcid.org/0000-0001-5679-6536>), Rosa Félix [aut] (ORCID: <https://orcid.org/0000-0002-5642-6006>), Joey Talbot [aut] (ORCID: <https://orcid.org/0000-0002-6520-4560>), Gonçalo Matos [aut] (ORCID: <https://orcid.org/0009-0001-3489-1732>), Dan Olner [rev] (Dan reviewed the package for rOpenSci, see https://github.com/ropensci/software-review/issues/420#issuecomment-857662657), Andy Teucher [rev] (Andy reviewed the package for rOpenSci, see https://github.com/ropensci/software-review/issues/420#issuecomment-858231647) GPL-3 2026-06-25 application/tgz https://CRAN.R-project.org/package=slopes doi:10.32614/CRAN.package.slopes