CODEWITHSUNDEEP
javaanylogicagent-based-modeling
Srijith Balakrishnan
Srijith Balakrishnan

Reputation: 13

Anylogic: Creating unidirectional connections to specific agents based on shortest distance

I am new to Anylogic, and would like to perform the following task. I have several types of immobile agents on a GIS environment and would like to connect them by a network. The condition for the connections is as follows: Let agent type A has 4 agents and agent type B has 20 agents. I want to connect B with A based on the shortest (straight line) distance. That is, an agent of type B is to be connected to the nearest agent of type A.

Thank you.

Upvotes: 0

Views: 371

Answers (1)

Dylan Knowles
Dylan Knowles

Reputation: 2803

In your specific case, this is what you want at the beginning of your model:

// For each of your Bs
for (Agent B : populationOfB) {
  // Find the nearest A (using a straight line) and connect.
  B.connections.connectTo(B.getNearestAgent(populationOfAgentA));
}

More generally, if you want a B to be connected to multiple A agents that match a particular set of conditions and you need to do that on the fly (or at the start of the model), you can do the following:

// For each B
for (Agent B : populationOfB) {

  // Find all A agents that it could possibly connect with.
  // Every time we take an agent from this collection, it will shrink to ensure we don't keep trying to connect to the same A.
  List<Agent> remainingOptions = filter(

    // We start with the full population of A
    populationOfAgentA, 

    // We don't want B to connect with any A it's already connected to, so filter them out.
    A -> B.connections.isConnectedTo(A) == false

      // You might want other conditions, such as maximum distance, some specific attribute such as affordability, etc.; simply add them here with a "&&"
      /* && <Any other condition you want, if you want it.>*/
  );

  // If B ideally wants N connections total, we then try to get it N connections. We don't start i at zero because it may already have connections.
  for (int i = B.connections.getConnectionsNumber(); i < N; i += 1) {

    // Find the nearest A. (You can sort based on any property here, but you'd need to write that logic yourself.)
    Agent nearestA = B.getNearestAgent(remainingOptions);

    // Connect to the nearest A.
    B.connections.connectTo(nearestA);

    // The A we just connected to is no longer a valid option for filling the network.       
    remainingOptions.remove(nearestA);

    // If there are no other remaining viable options, we need to either quit or do something about it.
    if (remainingOptions.isEmpty()) {
      traceln("Oops! Couldn't find enough As for this B: " + B);
      break;
    }
  }
}

Also note that I use connections a lot: you could substitute that for a more specific network if you need multiple collections such as work, school, and social networks.

Upvotes: 0

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