@turf/polygon-smooth

@turf/polygon-smooth

polygonSmooth

Smooths a Polygon or MultiPolygon. Based on Chaikin's algorithm. Warning: may create degenerate polygons.

Parameters

• inputPolys (FeatureCollection | Feature<(Polygon | MultiPolygon)>) (Multi)Polygon(s) to smooth
• options Object Optional parameters (optional, default {})
  • options.iterations string THe number of times to smooth the polygon. A higher value means a smoother polygon. (optional, default 1)

Examples

var polygon = turf.polygon([[[11, 0], [22, 4], [31, 0], [31, 11], [21, 15], [11, 11], [11, 0]]]);

var smoothed = turf.polygonSmooth(polygon, {iterations: 3})

//addToMap
var addToMap = [smoothed, polygon];

Returns FeatureCollection<Polygon> FeatureCollection containing the smoothed polygon/poylgons

---

This module is part of the Turfjs project, an open source module collection dedicated to geographic algorithms. It is maintained in the Turfjs/turf repository, where you can create PRs and issues.

Installation

Install this module individually:

$ npm install @turf/polygon-smooth

Or install the Turf module that includes it as a function:

$ npm install @turf/turf

Changelog

6.2.0

After a bit of hiatus, TurfJS is resuming releases.

⭐️ Major Updates

• ES Modules available for all packages
• Tree shaking should significantly reduce import size of @turf/turf
• Better support for ESM modules (PR https://github.com/Turfjs/turf/pull/1942 - Author @diachedelic)
• Clean-up of test and benchmark running to make publishing easier
• Enforce styling using Prettier
• Enable ESLint and get rid of unused variables
• Upgrade rollup for more correct javascript module builds
• Only include ES5 code

🚀 New Modules

[@turf/boolean-touches][boolean-touches]

Determines if two features touch but do not intersect

[@turf/boolean-valid][boolean-valid]

Checks if the geometry is a valid according to the OGC Simple Feature Specification

[@turf/quadrat-analysis][quadrat-analysis]

Performs a quadrat analysis on a set of points

[@turf/rectangle-grid][rectangle-grid]

Creates a grid of rectangles from a bounding box

[@turf/voroni][voronoi]

Typescript types for the options parameter have been fixed (PR https://github.com/Turfjs/turf/pull/1424 - Author @stevage)

[@turf/points-within-polygon][points-within-polygon]

Typescript types around the Feature's Properties will now be preserved. (PR https://github.com/Turfjs/turf/pull/1761 - Author @rugheid)

[@turf/rewind][rewind]

Typescript types for the 'reverse' option are now correct. Previously it was misnamed as 'reversed'. (PR https://github.com/Turfjs/turf/pull/1786 - Author @jonnycornwell)

[@turf/difference][difference]

No longer publishes an .mjs file.

[@turf/meta][meta]

No longer publishes an .mjs file.

[@turf/tag][tag]

Add MultiPolygon support. (PR https://github.com/Turfjs/turf/pull/1996 - Author bryceroney)

🐛 Bug Fixes

• @turf/centroid Don't visit first point twice when calculating centroid (PR https://github.com/Turfjs/turf/pull/1894 - Author @rowanwins)

• @turf/transform-translate Better handling of negative distances (PR https://github.com/Turfjs/turf/pull/1895 - Author @rowanwins)

• @turf/union, @turf/difference, @turf/intersect Use polygon-clipping library to fix correctness issues (PR https://github.com/Turfjs/turf/pull/1916 - Authors @mbullington, @ngottlieb)

• @turf/buffer Change default number of steps to 8, and actually support the steps option (PR https://github.com/Turfjs/turf/pull/1931 - Author stevenchanin)

• @turf/buffer Fix projection issues that produce undersized buffers at non-equatorial latitudes (PR https://github.com/Turfjs/turf/pull/1956 - Author dyakovlev)

• @turf/helpers Add runtime checks to point() method, fixing an API break (PR https://github.com/Turfjs/turf/pull/1964)

🏅 New Features/Enhancements

• @turf/boolean-overlap Better performance for MultiPoint geometries (PR https://github.com/Turfjs/turf/pull/1910 - Author @mfedderly)

• @turf/helpers Add hectares to convertArea (PR https://github.com/Turfjs/turf/pull/1943 - Author @DanielJDufour)

• @turf/great-circle Update Typescript types to support MultiLineString input (PR https://github.com/Turfjs/turf/pull/1928 - Author kronick)

📖 Documentation

• @turf/square-grid Clarify inputs (PR https://github.com/Turfjs/turf/pull/1885 - Author @raphael-leger)

• @turf/greater-circle Clarify properties option example (PR https://github.com/Turfjs/turf/pull/1888 - Author @chris-catignani)

⚠️ Breaking Change

• @turf/line-to-polygon no longer modifies its input unless the mutate option is true (PR https://github.com/Turfjs/turf/pull/1879 - Author @MortenBirk)

• @turf/unkink-polygon remove Number.prototype.modulo override (PR https://github.com/Turfjs/turf/pull/1978)