Package: tissot
Title: Tissot Indicatrix for Map Projection Distortion
Version: 0.3.0
Authors@R: c(
    person("Michael", "Sumner", email = "mdsumner@gmail.com", role = c("aut", "cre", "cph"), 
           comment = c(ORCID = "0000-0002-2471-7511")),
    person("Bill", "Huber", role = "aut", 
           comment = "original algorithm and calculations")
  )
Description: 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>.
License: MIT + file LICENSE
Encoding: UTF-8
LazyData: true
Roxygen: list(markdown = TRUE)
Depends: R (>= 3.6.0)
Imports: tibble, PROJ, graphics, grDevices, stats
Suggests: testthat (>= 3.0.0), knitr, rmarkdown, spelling
Config/testthat/edition: 3
URL: https://hypertidy.github.io/tissot/,
        https://github.com/hypertidy/tissot
BugReports: https://github.com/hypertidy/tissot/issues
Language: en-US
Config/roxygen2/version: 8.0.0
Config/pak/sysreqs: libproj-dev
Repository: https://hypertidy.r-universe.dev
Date/Publication: 2026-07-12 15:35:32 UTC
RemoteUrl: https://github.com/hypertidy/tissot
RemoteRef: HEAD
RemoteSha: 8fca11b3e4b3698428c858999027aca610ca91d8
NeedsCompilation: no
Packaged: 2026-07-12 15:44:01 UTC; root
Author: Michael Sumner [aut, cre, cph] (ORCID:
    <https://orcid.org/0000-0002-2471-7511>),
  Bill Huber [aut] (original algorithm and calculations)
Maintainer: Michael Sumner <mdsumner@gmail.com>