Update predator prey model to use RandomHelper and constant seed.

Author: etatara

PredatorPrey/PredatorPrey.rs/parameters.xml

@@ -19,7 +19,7 @@
 
 		/>
 				<parameter name="randomSeed" displayName="Default Random Seed" type="int" 
-						defaultValue="__NULL__"
+						defaultValue="2"
 						isReadOnly="false" 
 						converter="repast.simphony.parameter.StringConverterFactory$IntConverter"
 

PredatorPrey/launchers/PredatorPrey Server.launch

@@ -1,5 +1,8 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
 <launchConfiguration type="org.eclipse.jdt.launching.localJavaApplication">
+    <listAttribute key="org.eclipse.debug.ui.favoriteGroups">
+        <listEntry value="org.eclipse.debug.ui.launchGroup.run"/>
+    </listAttribute>
     <listAttribute key="org.eclipse.jdt.launching.CLASSPATH">
         <listEntry value="&lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot; standalone=&quot;no&quot;?&gt;&#13;&#10;&lt;runtimeClasspathEntry containerPath=&quot;org.eclipse.jdt.launching.JRE_CONTAINER&quot; path=&quot;2&quot; type=&quot;4&quot;/&gt;&#13;&#10;"/>
         <listEntry value="&lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot; standalone=&quot;no&quot;?&gt;&#13;&#10;&lt;runtimeClasspathEntry containerPath=&quot;REPAST_SIMPHONY_SERVER_LAUNCHER&quot; path=&quot;3&quot; type=&quot;4&quot;/&gt;&#13;&#10;"/>

PredatorPrey/src/PredatorPrey/agents/Grass.java

@@ -3,6 +3,7 @@
 import repast.simphony.context.Context;
 import repast.simphony.engine.environment.RunEnvironment;
 import repast.simphony.parameter.Parameters;
+import repast.simphony.random.RandomHelper;
 import repast.simphony.space.continuous.ContinuousSpace;
 import repast.simphony.space.grid.Grid;
 import repast.simphony.util.ContextUtils;
@@ -16,87 +17,87 @@
 public class Grass extends SimpleAgent {
 	private int countdown;   // coundown timer for grass to re-grow
 	private boolean alive;   // boolean for grass alive / dead
-	
+
 	private static final int ALIVE = 1;
 	private static final int DEAD = 0;
-	
-  // This constructor is used to create initial grass from the context creator
+
+	// This constructor is used to create initial grass from the context creator
 	public Grass(Context context, int x, int y ){
 		// Get the grass regrow time from the user parameters
 		Parameters p = RunEnvironment.getInstance().getParameters();
 		int regrowTime = (Integer)p.getValue("grassregrowthtime");
-		
-	  // add the grass to the root context
+
+		// add the grass to the root context
 		context.add(this);	
-		
+
 		// Set the initial countdown time from 0 to regrowTime
-		countdown = (int)(Math.random() * regrowTime);
-		
+		countdown = RandomHelper.nextIntFromTo(0, regrowTime);
+
 		// Randomly set the grass alive or dead
-		if (Math.random() <= 0.5)
+		if (RandomHelper.nextDouble() <= 0.5)
 			alive = true;
-		
+
 		else
 			alive = false;
-		
+
 		Grid grid = (Grid)context.getProjection("Simple Grid");
 		ContinuousSpace space = (ContinuousSpace)context.getProjection("Continuous Space");
-		
-	  // move the grass to its position on the patch grid
+
+		// move the grass to its position on the patch grid
 		grid.moveTo(this, x, y);   
-		
-    //  and to its position on the continuous space
+
+		//  and to its position on the continuous space
 		space.moveTo(this, x, y, 0);				
-		
-    GridValueLayer vl = (GridValueLayer)context.getValueLayer("Grass Field");
-		
+
+		GridValueLayer vl = (GridValueLayer)context.getValueLayer("Grass Field");
+
 		if (alive)
 			vl.set(ALIVE, grid.getLocation(this).toIntArray(null));
 		else
 			vl.set(DEAD, grid.getLocation(this).toIntArray(null));
 	}
-	
-  @Override
+
+	@Override
 	public void step(){
 		// If the grass is not alive
 		if (!alive){
 			// If the countdown has expired, then regrow the grass
-		  if (countdown <= 0){
-        // Get the grass regrow time from the user parameters
-		  	Parameters p = RunEnvironment.getInstance().getParameters();
+			if (countdown <= 0){
+				// Get the grass regrow time from the user parameters
+				Parameters p = RunEnvironment.getInstance().getParameters();
 				int regrowTime = (Integer)p.getValue("grassregrowthtime");
-				
-		  	alive = true;
-		  	updateValueLayer();
-		  	countdown = regrowTime; 
-		  }
-		  // Otherwise continue the regrow countdown
-		  else
-		  	countdown--;
+
+				alive = true;
+				updateValueLayer();
+				countdown = regrowTime; 
+			}
+			// Otherwise continue the regrow countdown
+			else
+				countdown--;
 		}
 	}
 
-  /**
-   * Called by sheep when they eay this grass.
-   */
-  public void consume(){
-  	alive = false;
-  	updateValueLayer();
-  }
-  
-  /**
-   * Update the value layer to reflect the status of the grass health.
-   */
-  private void updateValueLayer(){
-    GridValueLayer vl = (GridValueLayer)ContextUtils.getContext(this).getValueLayer("Grass Field");
-    Grid grid = (Grid)ContextUtils.getContext(this).getProjection("Simple Grid");
-    
+	/**
+	 * Called by sheep when they eay this grass.
+	 */
+	public void consume(){
+		alive = false;
+		updateValueLayer();
+	}
+
+	/**
+	 * Update the value layer to reflect the status of the grass health.
+	 */
+	private void updateValueLayer(){
+		GridValueLayer vl = (GridValueLayer)ContextUtils.getContext(this).getValueLayer("Grass Field");
+		Grid grid = (Grid)ContextUtils.getContext(this).getProjection("Simple Grid");
+
 		if (alive)
 			vl.set(ALIVE, grid.getLocation(this).toIntArray(null));
 		else
 			vl.set(DEAD, grid.getLocation(this).toIntArray(null));
-  }
-  
+	}
+
 	/**
 	 * @return if the sheep is alive.
 	 */

PredatorPrey/src/PredatorPrey/agents/Sheep.java

@@ -3,6 +3,7 @@
 import repast.simphony.context.Context;
 import repast.simphony.engine.environment.RunEnvironment;
 import repast.simphony.parameter.Parameters;
+import repast.simphony.random.RandomHelper;
 import repast.simphony.space.grid.Grid;
 import repast.simphony.space.grid.GridPoint;
 import repast.simphony.util.ContextUtils;
@@ -13,44 +14,44 @@
  * @author Eric Tatara 
  */
 public class Sheep extends SimpleAgent {
-	
-  // This constructor is used to create an offspring
+
+	// This constructor is used to create an offspring
 	public Sheep(double energy){
 		this.setEnergy(energy);               // assign the offspring energy
-		this.setHeading(Math.random()*360);   // randomize the heading from 0-360 degrees
+		this.setHeading(RandomHelper.nextDoubleFromTo(0,360));   // randomize the heading from 0-360 degrees
 	}
-  
+
 	// This constructor is used to create initial wolves from the context creator
 	public Sheep(){
-  //	 Get the value of the sheeep gain from food from the environment parameters
+		//	 Get the value of the sheeep gain from food from the environment parameters
 		Parameters p = RunEnvironment.getInstance().getParameters();
 		double gain = (Double)p.getValue("sheepgainfromfood");
-		
-		this.setEnergy(Math.random() * 2 * gain);    // set the initial energy
-		this.setHeading(Math.random()*360);          //  and initial heading
+
+		this.setEnergy(RandomHelper.nextDouble() * 2 * gain);    // set the initial energy
+		this.setHeading(RandomHelper.nextDoubleFromTo(0,360));   // randomize the heading from 0-360 degrees
 	}
-	
+
 	@Override
 	public void step() {
-    //	Get the context in which the sheep resides.
+		//	Get the context in which the sheep resides.
 		Context context = ContextUtils.getContext(this);
-		
+
 		// Move the sheep
 		move();
-		
-    //	Reduce the sheep's energy by one unit
+
+		//	Reduce the sheep's energy by one unit
 		this.setEnergy(this.getEnergy() - 1);
-		
+
 		// Eat Grass
 		// Get the patch grid from the context
 		Grid patch = (Grid) context.getProjection("Simple Grid");
-		
+
 		// Get the sheep's current patch
 		GridPoint point = patch.getLocation(this);
-		
+
 		int x = point.getX();   // The x-ccordinate of the sheep's current patch
 		int y = point.getY();   // The y-ccordinate of the sheep's current patch
-		
+
 		// Get the sheep gain from food from the user parameters
 		Parameters p = RunEnvironment.getInstance().getParameters();
 		double gain = (Double)p.getValue("sheepgainfromfood");
@@ -66,21 +67,21 @@ public void step() {
 			grass.consume();                    // eat the grass
 			this.setEnergy(this.getEnergy() + gain);  // increment the sheep's energy
 		}
-		
+
 		// Reproduce the sheep
 		// Get the reproduction rate from the user parameters
 		double rate = (Double)p.getValue("sheepreproduce");
-		
-    // Spawn a new sheep if a random draw on [0,100) < reproduction rate
-		if (100*Math.random() < rate){
+
+		// Spawn a new sheep if a random draw on [0,100) < reproduction rate
+		if (100 * RandomHelper.nextDouble() < rate){
 			this.setEnergy(this.getEnergy() / 2);	       // divide the parent's energy in half
 			Sheep sheep = new Sheep(this.getEnergy());   // create a new sheep offspring and assing its energy
 			context.add(sheep);                          // add the offspring to the root context
 		}
 
 		// Kill the sheep if its energy drops below zero
 		if (this.getEnergy() < 0)
-		 die();
+			die();
 	}
 
 	// Public getter for the data gatherer for counting sheep

PredatorPrey/src/PredatorPrey/agents/SimpleAgent.java

@@ -4,6 +4,7 @@
 import repast.simphony.context.Context;
 import repast.simphony.engine.environment.RunEnvironment;
 import repast.simphony.engine.schedule.ScheduledMethod;
+import repast.simphony.random.RandomHelper;
 import repast.simphony.space.continuous.ContinuousSpace;
 import repast.simphony.space.continuous.NdPoint;
 import repast.simphony.space.grid.Grid;
@@ -19,65 +20,65 @@
 public class SimpleAgent {
 	private double energy;       // The energy level of the agent
 	private double heading;      // The heading in degrees of the agent
-	
+
 	// Shedule the step method for agents.  The method is scheduled starting at 
 	// tick one with an interval of 1 tick.  Specifically, the step starts at 1, and
 	// and recurs at 2,3,4,...etc
 	@ScheduledMethod(start = 1, interval = 1, shuffle=true)
 	public void step() {
 		// Override by subclasses
 	}
-	
-  // Move the agent
+
+	// Move the agent
 	public void move() {
 		// The agent is aware of its location in the continuous space and
 		// which grass patch it is on
-		
+
 		// Get the context in which the agent is residing
 		Context context = ContextUtils.getContext(this);
-		
+
 		// Get the patch grid from the context
 		Grid patch = (Grid) context.getProjection("Simple Grid");
-		
+
 		// Get the continuous space from the context
 		ContinuousSpace space = (ContinuousSpace) context.getProjection("Continuous Space");
-		
+
 		NdPoint point = space.getLocation(this);  // Get the agent's point coordinate from the space
 
 		double x = point.getX();			// The x coordinate on the 2D continuous space
 		double y = point.getY();      // The y coordinate on the 2D continuous space
-		
+
 		// Randomly change the current heading plus or minus 50 degrees
-		double sgn = Math.random() - 0.5;       // a value between -0.5 and 0.5
+		double sgn = RandomHelper.nextDoubleFromTo(-0.5, 0.5);       // a value between -0.5 and 0.5
 		if (sgn > 0)
-		  heading = heading + Math.random()*50;
+			heading = heading + RandomHelper.nextDoubleFromTo(0, 50);
 		else
-			heading = heading - Math.random()*50;
-		
+			heading = heading - RandomHelper.nextDoubleFromTo(0, 50);
+
 		// Move the agent on the space by one unit according to its new heading
 		space.moveByVector(this, 1, Math.toRadians(heading),0,0);
-		
+
 		// Move the agent to its new patch (note the patch may not actually change)
 		patch.moveTo(this, (int)x, (int)y);	
 	}
-	
-  // Kill the agent
+
+	// Kill the agent
 	public void die(){
-    // Get the context in which the agent resides.
+		// Get the context in which the agent resides.
 		Context context = ContextUtils.getContext(this);
-		
-    // Remove the agent from the context if the context is not empty
+
+		// Remove the agent from the context if the context is not empty
 		if (context.size() > 1)
-		  context.remove(this); 
-    // Otherwise if the context is empty, end the simulation
+			context.remove(this); 
+		// Otherwise if the context is empty, end the simulation
 		else
 			RunEnvironment.getInstance().endRun();
 	}
-	
+
 	public int isSheep() {
 		return 0;
 	}
-	
+
 	public int isWolf() {
 		return 0;
 	}
@@ -97,5 +98,5 @@ public double getHeading() {
 	public void setHeading(double heading) {
 		this.heading = heading;
 	}
-	
+
 }