# @turf/standard-deviational-ellipse > Takes a collection of features and returns a standard deviational ellipse. Latest version **7.4.0** (published 2026-08-03) · MIT license · 0 weekly downloads ## Install ```sh npm install @turf/standard-deviational-ellipse pnpm add @turf/standard-deviational-ellipse yarn add @turf/standard-deviational-ellipse bun add @turf/standard-deviational-ellipse ``` ## Health **Score 80/100 (A)** — status: active. Positive: has types; esm support; no vulnerabilities; has provenance; recently updated; high maintenance score; high quality score; popular repo. Warnings: low downloads. ## Facts | | | |---|---| | Version | 7.4.0 | | Published | 2026-08-03 | | First published | 2017-11-27 | | Weekly downloads | 0 | | License | MIT | | TypeScript types | bundled | | Module format | ESM + CommonJS | | Dependencies | 8 | | Unpacked size | 38.1 KB | | Known vulnerabilities | 0 | | Install scripts | no | | Provenance | attested (GitHub Actions) | | GitHub stars | 10490 | | Author | Turf Authors | | Maintainers | rowanwins, tmcw, morganherlocker, tcql, mdfedderly, twelch, jamesmilneruk, morgan.herlocker | | Keywords | turf, standard-deviational-ellipse, geostatistics, directional distribution | ## Links - npm: https://www.npmjs.com/package/@turf/standard-deviational-ellipse - Repository: https://github.com/Turfjs/turf - Issues: https://github.com/Turfjs/turf/issues - Funding: https://opencollective.com/turf - npm.io page: https://npm.io/package/@turf/standard-deviational-ellipse ## Dependencies (8) - [tslib](https://npm.io/package/tslib.md) ^2.8.1 - [@turf/meta](https://npm.io/package/@turf/meta.md) 7.4.0 - [@turf/ellipse](https://npm.io/package/@turf/ellipse.md) 7.4.0 - [@turf/helpers](https://npm.io/package/@turf/helpers.md) 7.4.0 - [@types/geojson](https://npm.io/package/@types/geojson.md) ^7946.0.10 - [@turf/invariant](https://npm.io/package/@turf/invariant.md) 7.4.0 - [@turf/center-mean](https://npm.io/package/@turf/center-mean.md) 7.4.0 - [@turf/points-within-polygon](https://npm.io/package/@turf/points-within-polygon.md) 7.4.0 ## Recent versions - 7.4.0 (latest) — 2026-08-03 - 7.1.0-alpha.70 (prerelease) — 2024-08-09 - 7.3.5 — 2026-04-19 - 7.3.4 — 2026-02-08 - 7.3.3 — 2026-01-28 - 7.3.2 — 2026-01-14 - 7.3.1 — 2025-11-27 - 7.3.0 — 2025-11-17 - 7.2.0 — 2024-12-29 - 7.1.0 — 2024-08-09 - 7.1.0-alpha.7 — 2024-06-25 - 7.0.0 — 2024-06-07 - 7.0.0-alpha.116 — 2024-05-07 - 7.0.0-alpha.115 — 2024-04-23 - 7.0.0-alpha.114 — 2024-03-11 - … 17 more at https://npm.io/package/@turf/standard-deviational-ellipse/versions ## README # @turf/standard-deviational-ellipse ## standardDeviationalEllipse Takes a collection of features and returns a standard deviational ellipse, also known as a “directional distribution.” The standard deviational ellipse aims to show the direction and the distribution of a dataset by drawing an ellipse that contains about one standard deviation’s worth (\~ 70%) of the data. This module mirrors the functionality of [Directional Distribution][1] in ArcGIS and the [QGIS Standard Deviational Ellipse Plugin][2] **Bibliography** • Robert S. Yuill, “The Standard Deviational Ellipse; An Updated Tool for Spatial Description,” *Geografiska Annaler* 53, no. 1 (1971): 28–39, doi:{@link [https://doi.org/10.2307/490885|10.2307/490885}][3]. • Paul Hanly Furfey, “A Note on Lefever’s “Standard Deviational Ellipse,” *American Journal of Sociology* 33, no. 1 (1927): 94—98, doi:{@link [https://doi.org/10.1086/214336|10.1086/214336}][4]. ### Parameters * `points` **[FeatureCollection][5]<[Point][6]>** GeoJSON points * `options` **[Object][7]** Optional parameters (optional, default `{}`) * `options.weight` **[string][8]?** the property name used to weight the center * `options.steps` **[number][9]** number of steps for the polygon (optional, default `64`) * `options.properties` **[Object][7]** properties to pass to the resulting ellipse (optional, default `{}`) ### Examples ```javascript const bbox = [-74, 40.72, -73.98, 40.74]; const points = turf.randomPoint(400, {bbox: bbox}); const sdEllipse = turf.standardDeviationalEllipse(points); //addToMap const addToMap = [points, sdEllipse]; ``` Returns **[Feature][10]<[Polygon][11]>** an elliptical Polygon that includes approximately 1 SD of the dataset within it. [1]: http://desktop.arcgis.com/en/arcmap/10.3/tools/spatial-statistics-toolbox/directional-distribution.htm [2]: http://arken.nmbu.no/~havatv/gis/qgisplugins/SDEllipse/ [3]: https://doi.org/10.2307/490885|10.2307/490885} [4]: https://doi.org/10.1086/214336|10.1086/214336} [5]: https://tools.ietf.org/html/rfc7946#section-3.3 [6]: https://tools.ietf.org/html/rfc7946#section-3.1.2 [7]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object [8]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String [9]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number [10]: https://tools.ietf.org/html/rfc7946#section-3.2 [11]: https://tools.ietf.org/html/rfc7946#section-3.1.6 --- This module is part of the [Turfjs project](https://turfjs.org/), an open source module collection dedicated to geographic algorithms. It is maintained in the [Turfjs/turf](https://github.com/Turfjs/turf) repository, where you can create PRs and issues. ### Installation Install this single module individually: ```sh $ npm install @turf/standard-deviational-ellipse ``` Or install the all-encompassing @turf/turf module that includes all modules as functions: ```sh $ npm install @turf/turf ``` --- _Source: https://npm.io/package/@turf/standard-deviational-ellipse · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._