组装数据- 对象里面是key:value, value里面是数组的形式，如 {key:[aa,bb], key:[cc,dd]}

 data: {
              centerdata:[
                 {"city": "无锡市","clusterID": 1, "x": 120.7485913653,"y": 31.809979797058332},
                 {"city": "廊坊市","clusterID": 2,"x": 130.7485913653,"y": 39.215436433250005},
                 {"city": "金华市","clusterID": 3,"x": 140.7485913653,"y": 29.190387826775}
              ]
            },

  created() {
            for(var i=0;i<this.centerdata.length;i++){
              this.add(this.centerdata[i].city,[this.centerdata[i].x,this.centerdata[i].y])；//传参是重点
            }
          },
          
          methods: {
              add(key,value){
                let keyValue={}
                keyValue[key]=value;
                console.log(keyValue)
               }
          },