tissot: Tissot Indicatrix for Map Projection Distortion

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 'GDAL' for coordinate transformation. Developed using the method published in Snyder, JP (1987) <doi:10.3133/pp1395>.

Version:	0.2.0
Depends:	R (≥ 3.6.0)
Imports:	tibble, gdalraster, graphics, grDevices
Suggests:	testthat (≥ 3.0.0), knitr, rmarkdown, spelling
Published:	2026-02-12
DOI:	10.32614/CRAN.package.tissot (may not be active yet)
Author:	Michael Sumner [aut, cre], Bill Huber [aut] (original algorithm and calculations)
Maintainer:	Michael Sumner <mdsumner at gmail.com>
BugReports:	https://github.com/hypertidy/tissot/issues
License:	MIT + file LICENSE
URL:	https://github.com/hypertidy/tissot
NeedsCompilation:	no
Language:	en-US
Materials:	README, NEWS
CRAN checks:	tissot results

Documentation:

Reference manual:

tissot.html , tissot.pdf

Downloads:

Package source:	tissot_0.2.0.tar.gz
Windows binaries:	r-devel: not available, r-release: tissot_0.2.0.zip, r-oldrel: tissot_0.2.0.zip
macOS binaries:	r-release (arm64): tissot_0.2.0.tgz, r-oldrel (arm64): tissot_0.2.0.tgz, r-release (x86_64): tissot_0.2.0.tgz, r-oldrel (x86_64): tissot_0.2.0.tgz

Linking:

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