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- 'use strict';
- var helpers = require('@turf/helpers');
- var invariant = require('@turf/invariant');
- var d3voronoi = require('d3-voronoi');
- /**
- * @private
- * @param {Array<Array<number>>} coords representing a polygon
- * @returns {Feature<Polygon>} polygon
- */
- function coordsToPolygon(coords) {
- coords = coords.slice();
- coords.push(coords[0]);
- return helpers.polygon([coords]);
- }
- /**
- * Takes a FeatureCollection of points, and a bounding box, and returns a FeatureCollection
- * of Voronoi polygons.
- *
- * The Voronoi algorithim used comes from the d3-voronoi package.
- *
- * @name voronoi
- * @param {FeatureCollection<Point>} points to find the Voronoi polygons around.
- * @param {Object} [options={}] Optional parameters
- * @param {number[]} [options.bbox=[-180, -85, 180, -85]] clipping rectangle, in [minX, minY, maxX, MaxY] order.
- * @returns {FeatureCollection<Polygon>} a set of polygons, one per input point.
- * @example
- * var options = {
- * bbox: [-70, 40, -60, 60]
- * };
- * var points = turf.randomPoint(100, options);
- * var voronoiPolygons = turf.voronoi(points, options);
- *
- * //addToMap
- * var addToMap = [voronoiPolygons, points];
- */
- function voronoi(points, options) {
- // Optional params
- options = options || {};
- if (!helpers.isObject(options)) throw new Error("options is invalid");
- var bbox = options.bbox || [-180, -85, 180, 85];
- // Input Validation
- if (!points) throw new Error("points is required");
- if (!Array.isArray(bbox)) throw new Error("bbox is invalid");
- invariant.collectionOf(points, "Point", "points");
- // Main
- return helpers.featureCollection(
- d3voronoi.voronoi()
- .x(function (feature) {
- return feature.geometry.coordinates[0];
- })
- .y(function (feature) {
- return feature.geometry.coordinates[1];
- })
- .extent([
- [bbox[0], bbox[1]],
- [bbox[2], bbox[3]],
- ])
- .polygons(points.features)
- .map(coordsToPolygon)
- );
- }
- module.exports = voronoi;
- module.exports.default = voronoi;
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