如何计算Neo4j中浮点值的等级? [英] How to calculate rank for float values in Neo4j?

问题描述

我正在使用apoc.algo.dijkstra计算一组路径.我的目标是为每个建议的路径分配一个等级.重要的是节点之间的所有权重都是浮点数.密码:

I am calculating a set of paths using apoc.algo.dijkstra. My goal is to assign a rank to each of the suggested paths. Important is all the weights among nodes are floats. Cypher code:

 ...
 WITH origin, target CALL apoc.algo.dijkstra(origin, target, 'link', 
 'Weight') yield path as path, weight as weight
 ...

我现在所拥有的:

Path 1 - Weight: 1.2344332423
Path 2 - Weight: 0.8432423321
Path 3 - Weight: 0.9144331653

我需要的是:

rank: 1, weight: 1.2344332423
rank: 2, weight: 0.9144331653
rank: 3, weight: 0.8432423321

如何在Cypher查询中执行此操作.

How can I do this inside the Cypher query.

注意:我已经阅读了有关计算排名的文章，但是不适合我的具体情况.

Note: I already read the post related to calculating the rank, but it doesn't suit to my specific case.

如何在Neo4j中计算排名

谢谢！

其他信息: 我现在尝试将等级和权重值与原点和路径合并.我可以成功地将此作为来源:

Additional info: I am trying now to merge the ranking and wight values with origin and path. I could succesully do this for origin:

 CALL 
 apoc.load.json("file:///.../input.json") YIELD value 
 UNWIND value.origin AS orig 
 MATCH(origin:concept{name:orig.label}) WITH value, collect(origin) as 
 origins 
 UNWIND value.target AS tar MATCH(target:concept{name:tar.label}) 
 UNWIND origins AS origin WITH origin, target 
 CALL apoc.algo.dijkstra(origin, target, 'link', 'Weight') yield path as 
 path, weight as weight 
 WITH origin, path, weight ORDER BY weight ASC WITH {origin: origin, weight: 
 collect(weight)} AS SuggestionForOrigin UNWIND [r in range(1, 
 SIZE(SuggestionForOrigin.weight)) | {origin: SuggestionForOrigin.origin, 
 rank:r, weight: SuggestionForOrigin.weight[r-1]}] AS suggestion RETURN 
 suggestion

然后我得到以下结果(这对我来说很令人满意):

Then I get the following result (which is satisfying for me):

 {"origin": {"name": "A","type": "string"},"rank": 1,"weight": 0.0}
 {"origin": {"name": "A","type": "string"},"rank": 2,"weight": 
 0.6180339887498948}
 {"origin": {"name": "P1","type": "string"},"rank": 1,"weight": 
 0.6180339887498948}
 {"origin": {"name": "P1","type": "string"},"rank": 2,"weight": 
 1.2360679774997896}

但是当我尝试合并"path"参数时，我遇到了麻烦.我认为，我对这些东西补偿过高.我想实现的目标是:

But when I am trying to merge "path" parameter, I am getting into trouble. I think, I overcompensate the things. Something what I would like to achieve is:

 {"origin": {....}, "path": {...}, "rank": 1,"weight": 0.0}

这需要与特定的原始节点有关，如果我对第一个原始节点有3条路径建议，则需要将它们组合在一起.我已经尝试过，但是无法按我的意愿进行操作:

And this need to be related to a particular origin node, if I have 3 paths suggestions for the first origin, they need to be combined together. What I#ve tried, but it doesn't work as I want is:

 ...
 CALL apoc.algo.dijkstra(origin, target, 'link', 'Weight') yield path as 
 path, weight 
 WITH {origin: origin, path: collect(path), weight: collect(weight)} AS 
 SuggestionForOrigin 
 UNWIND [r in range(1, SIZE(SuggestionForOrigin.weight)) | {rank:r, weight: 
 SuggestionForOrigin.weight[r-1], path: SuggestionForOrigin}] AS suggestion 
 WITH {origin: SuggestionForOrigin.origin, suggestions: collect(suggestion) 
 [0..3]} AS output 
 RETURN output

如果您能提供帮助，我将不胜感激.

I would appreciate, if you could help.

推荐答案

这可能对您有用:

...
WITH origin, target
CALL apoc.algo.dijkstra(origin, target, 'link', 'Weight') YIELD weight
WITH weight
ORDER BY weight DESC
WITH COLLECT(weight) AS ws
UNWIND [r IN RANGE(1, SIZE(ws)) | {rank:r, weight: ws[r-1]}] AS res
RETURN res;

结果(假设您的样本数据)如下:

The result (assuming your sample data) would look like this:

╒════════════════════════════════╕
│"res"                           │
╞════════════════════════════════╡
│{"rank":1,"weight":1.2344332423}│
├────────────────────────────────┤
│{"rank":2,"weight":0.9144331653}│
├────────────────────────────────┤
│{"rank":3,"weight":0.8432423321}│
└────────────────────────────────┘

[更新]

如果您还希望返回origin和path(并按升序排列)，请参见此答案.

If you want to also return the origin and path (and rank by ascending weight), see this answer.

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