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apoc.algo.aStarConfig

详情
语法	`apoc.algo.aStarConfig(startNode, endNode, relTypesAndDirections, config) :: (path, weight)`
描述	运行 A* 搜索算法，使用给定 `RELATIONSHIP` 属性名称作为成本函数，查找两个 `NODE` 值之间的最优路径。此过程在配置中查找权重、纬度和经度属性。
输入参数	名称	类型	描述
	`startNode`	`NODE`	搜索的起始节点。
	`endNode`	`NODE`	搜索的结束节点。
	`relTypesAndDirections`	`STRING`	用于限制算法的关系类型。关系类型使用 APOC 的关系方向模式语法表示；`[<]RELATIONSHIP_TYPE1[>]\|[<]RELATIONSHIP_TYPE2[>]\|…`。
	`config`	`MAP`	{ weight = 'distance' :: STRING, default = Double.MAX_VALUE :: FLOAT, y = 'latitude' :: STRING, x = 'longitude' :: STRING, pointPropName :: STRING }
返回参数	名称	类型	描述
	`path`	`PATH`	路径结果。
	`weight`	`FLOAT`	给定路径的权重。

示例

给定此数据集

CREATE (b:City {name:'Berlin', coords: point({latitude:52.52464,longitude:13.40514}), lat:52.52464,lon:13.40514})
CREATE (m:City {name:'München', coords: point({latitude:48.1374,longitude:11.5755}), lat:48.1374,lon:11.5755})
CREATE (f:City {name:'Frankfurt',coords: point({latitude:50.1167,longitude:8.68333}), lat:50.1167,lon:8.68333})
CREATE (h:City {name:'Hamburg', coords: point({latitude:53.554423,longitude:9.994583}), lat:53.554423,lon:9.994583})
CREATE (b)-[:DIRECT {dist:255.64*1000}]->(h)
CREATE (b)-[:DIRECT {dist:504.47*1000}]->(m)
CREATE (b)-[:DIRECT {dist:424.12*1000}]->(f)
CREATE (f)-[:DIRECT {dist:304.28*1000}]->(m)
CREATE (f)-[:DIRECT {dist:393.15*1000}]->(h)

可以执行以下查询（利用作为数字的 lat 和 lon 节点属性，以及 dist 关系属性，默认成本为 100）

MATCH (from:City {name:'München'}), (to:City {name:'Hamburg'})
CALL apoc.algo.aStarConfig(from, to, 'DIRECT', {weight:'dist',y:'lat', x:'lon',default:100})
YIELD weight, path
RETURN weight, path

weight path

结果
weight	path
697430.0	{ "start": { "identity": 1520006, "labels": [ "City" ], "properties": { "name": "München", "lon": 11.5755, "lat": 48.1374, "coords": point({srid:4326, x:11.5755, y:48.1374}) } }, "end": { "identity": 1520008, "labels": [ "City" ], "properties": { "name": "Hamburg", "lon": 9.994583, "lat": 53.554423, "coords": point({srid:4326, x:9.994583, y:53.554423}) } }, "segments": [ { "start": { "identity": 1520006, "labels": [ "City" ], "properties": { "name": "München", "lon": 11.5755, "lat": 48.1374, "coords": point({srid:4326, x:11.5755, y:48.1374}) } }, "relationship": { "identity": 3, "start": 1520007, "end": 1520006, "type": "DIRECT", "properties": { "dist": 304280.0 } }, "end": { "identity": 1520007, "labels": [ "City" ], "properties": { "name": "Frankfurt", "lon": 8.68333, "lat": 50.1167, "coords": point({srid:4326, x:8.68333, y:50.1167}) } } }, { "start": { "identity": 1520007, "labels": [ "City" ], "properties": { "name": "Frankfurt", "lon": 8.68333, "lat": 50.1167, "coords": point({srid:4326, x:8.68333, y:50.1167}) } }, "relationship": { "identity": 4, "start": 1520007, "end": 1520008, "type": "DIRECT", "properties": { "dist": 393150.0 } }, "end": { "identity": 1520008, "labels": [ "City" ], "properties": { "name": "Hamburg", "lon": 9.994583, "lat": 53.554423, "coords": point({srid:4326, x:9.994583, y:53.554423}) } } } ], "length": 2.0 }

697430.0

{
  "start": {
"identity": 1520006,
"labels": [
      "City"
    ],
"properties": {
"name": "München",
"lon": 11.5755,
"lat": 48.1374,
"coords": point({srid:4326, x:11.5755, y:48.1374})
    }
  },
  "end": {
"identity": 1520008,
"labels": [
      "City"
    ],
"properties": {
"name": "Hamburg",
"lon": 9.994583,
"lat": 53.554423,
"coords": point({srid:4326, x:9.994583, y:53.554423})
    }
  },
  "segments": [
    {
      "start": {
"identity": 1520006,
"labels": [
          "City"
        ],
"properties": {
"name": "München",
"lon": 11.5755,
"lat": 48.1374,
"coords": point({srid:4326, x:11.5755, y:48.1374})
        }
      },
      "relationship": {
"identity": 3,
"start": 1520007,
"end": 1520006,
"type": "DIRECT",
"properties": {
"dist": 304280.0
        }
      },
      "end": {
"identity": 1520007,
"labels": [
          "City"
        ],
"properties": {
"name": "Frankfurt",
"lon": 8.68333,
"lat": 50.1167,
"coords": point({srid:4326, x:8.68333, y:50.1167})
        }
      }
    },
    {
      "start": {
"identity": 1520007,
"labels": [
          "City"
        ],
"properties": {
"name": "Frankfurt",
"lon": 8.68333,
"lat": 50.1167,
"coords": point({srid:4326, x:8.68333, y:50.1167})
        }
      },
      "relationship": {
"identity": 4,
"start": 1520007,
"end": 1520008,
"type": "DIRECT",
"properties": {
"dist": 393150.0
        }
      },
      "end": {
"identity": 1520008,
"labels": [
          "City"
        ],
"properties": {
"name": "Hamburg",
"lon": 9.994583,
"lat": 53.554423,
"coords": point({srid:4326, x:9.994583, y:53.554423})
        }
      }
    }
  ],
  "length": 2.0
}

或者等效地，使用相同的配置，利用作为 Point 类型的 coords 节点属性，获得相同的结果。请注意，在 3D 坐标的情况下，该过程将只选择 x 和 y 或经度和纬度值。

MATCH (from:City {name:'München'}), (to:City {name:'Hamburg'})
CALL apoc.algo.aStarConfig(from, to, 'DIRECT', {pointPropName:'coords', weight:'dist', default:100})
YIELD weight, path
RETURN weight, path