Javascript 如何使用Mapbox'；s簇？

我正在用Mabpox gl js v0.45对集群进行POC

我想自定义集群的属性（实际默认值是point_count和point_count_缩写）。我的每个点（每个城市一个）都有一个曲面特性（整数），我希望在聚集点时对其求和

我在对用于计算自定义属性的reduce函数的引用中看到：

SuperCluster.prototype = {
    options: {
        minZoom: 0,   // min zoom to generate clusters on
        // .....
        log: false,   // whether to log timing info

        // a reduce function for calculating custom cluster properties
        reduce: null, // function (accumulated, props) { accumulated.sum += props.sum; }

        // initial properties of a cluster (before running the reducer)
        initial: function () { return {}; }, // function () { return {sum: 0}; },

        // properties to use for individual points when running the reducer
        map: function (props) { return props; } // function (props) { return {sum: props.my_value}; },
    },

但我在文档中没有看到任何关于它的提及如何设置这些选项？

Mapbox似乎没有发布这些接口（），也没有提到：

---

它看起来像是一个普通的减压阀。它将为每个点调用一个，并允许您使用点的属性为整个集群创建属性

所以如果你这样定义你的reduce

supercluster({
  reduce: (clusterProps, pointProps) => {
    clusterProps.sum += pointProps.surface;
  }
});

---

然后集群上的

sum

属性将是点上所有

surface

属性的总和。

有人给了我一个解决方法：不要使用嵌入式supecluster，而是创建自己的supecluster并将其用作源：

var myCluster = supercluster({
    radius: 40,
    maxZoom: 16,
    reduce: function(p) { /* I can use reduce/map/... functions! */ }
});

// My clustered source is created without Mapbox's clusters since I managed my clusters outside Mapbox library.
map.addSource("earthquakes", {
    type: "geojson",
    data : {
      "type" : "FeatureCollection",
      "features" : []
    }
});

function loadRemoteGeoJson() {
    var features
    // Do what you want, when you want to retrieve remote features...
    // ...
    // In the end set features into your supercluster
    myCluster.load(features)
    pushClusterIntoMapbox(map)
}

// Function to call when you load remote data AND when you zoom in or out !
function pushClusterIntoMapbox(map) {
  // I maybe should be bounded here...
  var clusters = myCluster.getClusters([ -180.0000, -90.0000, 180.0000, 90.0000 ], Math
      .floor(map.getZoom()))

  // My colleague advice me to use http://turfjs.org as helper but I think it's quite optionnal
  var features = turf.featureCollection(clusters)
  map.getSource("earthquakes").setData(features)
}

---

我可能不太清楚我的问题，我想知道如何设置这些方法，这些方法似乎不会被Mapbox的API暴露给用户。这看起来很有趣。不过，我很难用一个简单的geojson示例来理解如何实现它。我刚刚问了一个与数据集相关的问题，如果你有时间看一看的话：Mapbox仍然没有集成超级星团，所以我们只能用Mapbox来做。我还想使用supercluster，但我能找到的唯一一个map/reduce函数的示例被破坏（放大时），并且没有包含注释，因此有点难以理解。当缩放级别足够高时，它也不会显示未聚集的点。我在一个新问题中提到了所有这些。你介意看一下吗：

var myCluster = supercluster({
    radius: 40,
    maxZoom: 16,
    reduce: function(p) { /* I can use reduce/map/... functions! */ }
});

// My clustered source is created without Mapbox's clusters since I managed my clusters outside Mapbox library.
map.addSource("earthquakes", {
    type: "geojson",
    data : {
      "type" : "FeatureCollection",
      "features" : []
    }
});

function loadRemoteGeoJson() {
    var features
    // Do what you want, when you want to retrieve remote features...
    // ...
    // In the end set features into your supercluster
    myCluster.load(features)
    pushClusterIntoMapbox(map)
}

// Function to call when you load remote data AND when you zoom in or out !
function pushClusterIntoMapbox(map) {
  // I maybe should be bounded here...
  var clusters = myCluster.getClusters([ -180.0000, -90.0000, 180.0000, 90.0000 ], Math
      .floor(map.getZoom()))

  // My colleague advice me to use http://turfjs.org as helper but I think it's quite optionnal
  var features = turf.featureCollection(clusters)
  map.getSource("earthquakes").setData(features)
}