Question

Merges a specified property from a FeatureCollection of points into a FeatureCollection of polygons. Given an inProperty on points and an outProperty for polygons, this finds every point that lies within each polygon, collects the inProperty values from those points, and adds them as an array to outProperty on the polygon.
将指定属性从点的FeatureCollection合并到一个FeatureCollection的多边形。给定点上的inProperty和多边形的outProperty，它将查找每个多边形内的所有点，从这些点收集inProperty值，并将它们作为数组添加到多边形上的outProperty中。

将指定的属性从点 FeatureCollection 合并为多边形 FeatureCollection。给定点的 inProperty 和多边形的 outProperty，此方法会找到每个多边形内的所有点，收集这些点的 inProperty 值，并将它们作为数组添加到多边形的 outProperty 中。

参数

参数	类型	描述
polygons	FeatureCollection <Polygon>	用于聚合的多边形
points	FeatureCollection <Point>	需要聚合的点
inProperty	string	需要嵌套的属性
outProperty	string	需要嵌套的属性

返回

FeatureCollection <Polygon> - 基于outField列出属性的多边形

示例

// 注意：polygon首尾坐标要一致
var poly1 = turf.polygon([[[0,0],[10,0],[10,10],[0,10],[0,0]]]);
var poly2 = turf.polygon([[[10,0],[20,10],[20,20],[20,0],[10,0]]]);
var polyFC = turf.featureCollection([poly1, poly2]);
var pt1 = turf.point([5,5], {population: 200});
var pt2 = turf.point([1,3], {population: 600});
var pt3 = turf.point([14,2], {population: 100});
var pt4 = turf.point([13,1], {population: 200});
var pt5 = turf.point([19,7], {population: 300});
var pointFC = turf.featureCollection([pt1, pt2, pt3, pt4, pt5]);
var collected = turf.collect(polyFC, pointFC, 'population', 'values');
var values = collected.features[0].properties.values
//=values => [200, 600]