Question

I am trying to get coordinates for turtles in NetLogo by using the Java API. I have managed to get the workspace loaded and have been using the following code that I made:

public static int getX(HeadlessWorkspace workspace, String playerName, int agentNum)
{

    Double doubleX = null;
    int xVal = 0;
    try
    {
        xVal = doubleX.valueOf((workspace.report("[xcor] of "+playerName+" "+agentNum).toString()).trim()).intValue();
    }
    catch(Exception ex)
    {
        ex.printStackTrace();
    }
    return xVal;
}

However, there is one small problem. It is extremely slow when there are more than 5 turtles. When I run the Flocking code with 200 turtles, without getting the coordinates, then I get about 300 ticks in 10 seconds. When I run the code with the coordinates, then each tick takes about 3 seconds. Is there a more efficient way of achieving this?

Thanks,

Nadim

Answer 1

I managed to find out what the proper way should be. This is the code in the NetLogo mailing list as given by Seth Tisue.

import org.nlogo.headless.*;
import org.nlogo.api.*;
class J {
   public static void main(String[] args) {
      try {
         HeadlessWorkspace ws = HeadlessWorkspace.newInstance();
         ws.openString(org.nlogo.util.Utils.url2String("/system/empty.nlogo"));
         ws.command("cro 8 [ fd 5 ]");
         org.nlogo.api.Turtle turtle =(org.nlogo.api.Turtle) ws.world().turtles().agent(3);
         System.out.println("[xcor] of turtle 3 = " + turtle.xcor());
         ws.dispose();
      }
      catch(Exception ex) {
         ex.printStackTrace();
      }
   }
}

I have reproduced the code here so it may benefit others. To see a list of what information you can get from Turtle, look at the NetLogo API documentation.

Nadim