# @turf/rewind ## rewind Rewind [(Multi)LineString][1] or [(Multi)Polygon][2] outer ring counterclockwise and inner rings clockwise (Uses [Shoelace Formula][3]). ### Parameters * `geojson` **[GeoJSON][4]** input GeoJSON Polygon * `options` **[Object][5]** Optional parameters (optional, default `{}`) * `options.reverse` **[boolean][6]** enable reverse winding (optional, default `false`) * `options.mutate` **[boolean][6]** allows GeoJSON input to be mutated (significant performance increase if true) (optional, default `false`) ### Examples ```javascript var polygon = turf.polygon([[[121, -29], [138, -29], [138, -18], [121, -18], [121, -29]]]); var rewind = turf.rewind(polygon); //addToMap var addToMap = [rewind]; ``` Returns **[GeoJSON][4]** rewind Polygon [1]: https://tools.ietf.org/html/rfc7946#section-3.1.4 [2]: https://tools.ietf.org/html/rfc7946#section-3.1.6 [3]: http://en.wikipedia.org/wiki/Shoelace_formula [4]: https://tools.ietf.org/html/rfc7946#section-3 [5]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object [6]: https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean --- 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/rewind ``` Or install the all-encompassing @turf/turf module that includes all modules as functions: ```sh $ npm install @turf/turf ```