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Create group ID based on conditions?

aron
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The two lines below share the same end nodes and I want to give them a common group id for later processing. This is to be the step after a TopologyBuilder.

I thought this would be pretty simple, but have run aground. So how do I achieve this?

The geometris are to be left unchanged. I just want them to have a common “id” if they intersect at both ends.

The conditions for the ‘join’ are:

_from_node = _from_node AND _to_node = _to_node

OR

_from_node = _to_node AND _to_node = _from_node

Because sometimes the lines orient in different directions.

 

 

Best answer by takashi

Hi ​@aron ,

My idea is to create group ID by concatenating “_from_node” and “_to_node” with ascending order. The concept is shown below.

  • _node1 = If _from_node < _to_node then _from_node, Else _to_node
  • _node2 = If _from_node < _to_node then _to_node, Else _from_node
  • _group_id = @Value(_node1)_@Value(_node2) 
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    danilo_fme
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    • danilo_fme
      danilo_fme
    Did this help you find an answer to your question?

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    takashi
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    • April 4, 2025

    Hi ​@aron ,

    My idea is to create group ID by concatenating “_from_node” and “_to_node” with ascending order. The concept is shown below.

    • _node1 = If _from_node < _to_node then _from_node, Else _to_node
    • _node2 = If _from_node < _to_node then _to_node, Else _from_node
    • _group_id = @Value(_node1)_@Value(_node2) 
    geomancer
    1 person upvoted this
    • geomancer
      geomancer
    geomancer
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    • geomancerEvangelist
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    • April 4, 2025
    takashi wrote:

    My idea is to create group ID by concatenating “_from_node” and “_to_node” with ascending order. 

    A very simple and elegant solution!

    If you want to, you can skip creating _node1 and _node2 by using _group_id =  @min(@Value(_from_node),@Value(_to_node))_@max(@Value(_from_node),@Value(_to_node))

     

    takashi
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    • takashi
      takashi
    ebygomm
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    • ebygommInfluencer
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    • April 4, 2025

    Would the NetworkTopologyCalculator not do this for you? 

    aron
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    • April 4, 2025
    ebygomm wrote:

    Would the NetworkTopologyCalculator not do this for you? 

    I believe that it would not get me where I want. There might be some trick with the NetworkTopologyCalculator that I dont know of, but when I have used it previously it gave me a ID for all the connected lines. I want to group only those that share the same start and end.

    ebygomm
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    • ebygommInfluencer
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    • April 4, 2025

    Ah too early in the morning for me, you’re actually looking for rings?

    aron
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    • April 4, 2025
    ebygomm wrote:

    Ah too early in the morning for me, you’re actually looking for rings?

    I haven't thought about it that way, but two part rings would be an accurate description. AreaBuilder does not work for my use case though, it gives far to many false positives. 

    Reply


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