地理距离(geo_distance)聚合

一个多桶聚合,作用于 geo_point 字段,在概念上与range聚合非常相似。 用户可以定义一个原点和一组距离范围桶。 该聚合计算每个文档值与原点的距离,并根据范围确定其所属的桶(如果文档与原点之间的距离在该桶的距离范围内,则该文档属于该桶)。

PUT /museums
{
    "mappings": {
        "properties": {
            "location": {
                "type": "geo_point"
            }
        }
    }
}

POST /museums/_bulk?refresh
{"index":{"_id":1}}
{"location": "52.374081,4.912350", "name": "NEMO Science Museum"}
{"index":{"_id":2}}
{"location": "52.369219,4.901618", "name": "Museum Het Rembrandthuis"}
{"index":{"_id":3}}
{"location": "52.371667,4.914722", "name": "Nederlands Scheepvaartmuseum"}
{"index":{"_id":4}}
{"location": "51.222900,4.405200", "name": "Letterenhuis"}
{"index":{"_id":5}}
{"location": "48.861111,2.336389", "name": "Musée du Louvre"}
{"index":{"_id":6}}
{"location": "48.860000,2.327000", "name": "Musée d'Orsay"}

POST /museums/_search?size=0
{
    "aggs" : {
        "rings_around_amsterdam" : {
            "geo_distance" : {
                "field" : "location",
                "origin" : "52.3760, 4.894",
                "ranges" : [
                    { "to" : 100000 },
                    { "from" : 100000, "to" : 300000 },
                    { "from" : 300000 }
                ]
            }
        }
    }
}

响应:

{
    ...
    "aggregations": {
        "rings_around_amsterdam" : {
            "buckets": [
                {
                    "key": "*-100000.0",
                    "from": 0.0,
                    "to": 100000.0,
                    "doc_count": 3
                },
                {
                    "key": "100000.0-300000.0",
                    "from": 100000.0,
                    "to": 300000.0,
                    "doc_count": 1
                },
                {
                    "key": "300000.0-*",
                    "from": 300000.0,
                    "doc_count": 2
                }
            ]
        }
    }
}

指定字段的类型必须是geo_point (只能在映射中显式设置)。 它还可以保存一个geo_point字段数组,在这种情况下,所有这些都将在聚合过程中考虑在内。 原点可以接受geo_point 类型支持的所有格式:

  • 对象格式: { "lat" : 52.3760, "lon" : 4.894 } - 这是最安全的格式,因为它对latlon值最明确
  • 字符串格式:"52.3760, 4.894" - 第一个值是lat,第二个是lon
  • 数组格式:[4.894, 52.3760] - 基于GeoJson标准,第一个值是lon,第二个是lat

默认情况下,距离的单位是 m (米),但也接受:mi (英里), in (英尺), yd (码), km (千米), cm (厘米), mm (毫米).

POST /museums/_search?size=0
{
    "aggs" : {
        "rings" : {
            "geo_distance" : {
                "field" : "location",
                "origin" : "52.3760, 4.894",
                "unit" : "km", 
                "ranges" : [
                    { "to" : 100 },
                    { "from" : 100, "to" : 300 },
                    { "from" : 300 }
                ]
            }
        }
    }
}

距离将以千米为单位计算

有两种距离计算模式:arc (默认) 和 planearc计算是最精确的,plane 最快但最不精确。 当搜索环境“狭窄”,并且跨越较小的地理区域(约5公里)时,请考虑使用plane。 对于非常大的区域的搜索(例如跨洲搜索),plane将返回更高的误差。。 可以使用参数distance_type设置距离计算类型:

POST /museums/_search?size=0
{
    "aggs" : {
        "rings" : {
            "geo_distance" : {
                "field" : "location",
                "origin" : "52.3760, 4.894",
                "unit" : "km",
                "distance_type" : "plane",
                "ranges" : [
                    { "to" : 100 },
                    { "from" : 100, "to" : 300 },
                    { "from" : 300 }
                ]
            }
        }
    }
}

keyed 响应

keyed 标志设置为 true会将唯一的字符串键与每个桶相关联,并将范围作为哈希而不是数组返回:

POST /museums/_search?size=0
{
    "aggs" : {
        "rings_around_amsterdam" : {
            "geo_distance" : {
                "field" : "location",
                "origin" : "52.3760, 4.894",
                "ranges" : [
                    { "to" : 100000 },
                    { "from" : 100000, "to" : 300000 },
                    { "from" : 300000 }
                ],
                "keyed": true
            }
        }
    }
}

响应:

{
    ...
    "aggregations": {
        "rings_around_amsterdam" : {
            "buckets": {
                "*-100000.0": {
                    "from": 0.0,
                    "to": 100000.0,
                    "doc_count": 3
                },
                "100000.0-300000.0": {
                    "from": 100000.0,
                    "to": 300000.0,
                    "doc_count": 1
                },
                "300000.0-*": {
                    "from": 300000.0,
                    "doc_count": 2
                }
            }
        }
    }
}

也可以为每个范围定制一个键:

POST /museums/_search?size=0
{
    "aggs" : {
        "rings_around_amsterdam" : {
            "geo_distance" : {
                "field" : "location",
                "origin" : "52.3760, 4.894",
                "ranges" : [
                    { "to" : 100000, "key": "first_ring" },
                    { "from" : 100000, "to" : 300000, "key": "second_ring" },
                    { "from" : 300000, "key": "third_ring" }
                ],
                "keyed": true
            }
        }
    }
}

响应:

{
    ...
    "aggregations": {
        "rings_around_amsterdam" : {
            "buckets": {
                "first_ring": {
                    "from": 0.0,
                    "to": 100000.0,
                    "doc_count": 3
                },
                "second_ring": {
                    "from": 100000.0,
                    "to": 300000.0,
                    "doc_count": 1
                },
                "third_ring": {
                    "from": 300000.0,
                    "doc_count": 2
                }
            }
        }
    }
}