levelSets: Ray-Based Mapping and Visualization of Level Sets (Excursion Sets)

An (upper) level set of a function is the set of inputs for which the function value is at or above a specified threshold. (Also called an excursion set). Applications of level sets include confidence or credible regions for parameters of statistical models, where the function is the likelihood or posterior density; regions where classification rules assign high probability to a given class; and scientific or engineering models where one is interested in input regions for which model output is above a threshold. This package maps out the boundary of a level set by finding its intersections with collections of 1-dimensional rays, generalizing a proposal by Kim and Lindsay (Statistica Sinica 21:923-948, 2011). Tools are provided to generate rays, find intersections, and visualize results. The package makes few assumptions about the studied function: it may be discontinuous, it may have a complicated feasible region, and the target level set may be non-convex or have multiple, disconnected parts. Vignettes describe package usage and show examples with two to five input space dimensions.

Version: 0.8.2
Depends: R (≥ 3.5.0)
Imports: graphics, stats, tools, utils, proxy, withr
Suggests: ggplot2, randomForest, palmerpenguins, knitr, rmarkdown
Published: 2026-06-22
DOI: 10.32614/CRAN.package.levelSets (may not be active yet)
Author: Richard Raubertas [aut, cre]
Maintainer: Richard Raubertas <rrprf at emvt.net>
License: GPL (≥ 3)
NeedsCompilation: no
Materials: NEWS
CRAN checks: levelSets results

Documentation:

Reference manual: levelSets.html , levelSets.pdf
Vignettes: The levelSets Package (source, R code)
Problem Setup (source, R code)
Confidence Regions (source, R code)
Classifiers (source, R code)

Downloads:

Package source: levelSets_0.8.2.tar.gz
Windows binaries: r-devel: not available, r-release: not available, r-oldrel: not available
macOS binaries: r-release (arm64): levelSets_0.8.2.tgz, r-oldrel (arm64): levelSets_0.8.2.tgz, r-release (x86_64): levelSets_0.8.2.tgz, r-oldrel (x86_64): levelSets_0.8.2.tgz

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