Simulation Chart Annotation usage

The MiniReal system gives realtime visualization (insight) of simulation models through a line chart on the browser. This line chart module receives an integer value from the simulation on each tick and displays it accordingly.

• The simulation model must have one or more methods that calculate some aggregate behaviour and return an integer value for each tick.
• Then users have to annotate such methods with the @SimChart annotation. This annotation takes argument with the keyword called name for the chart name. The value for this argument should be passed as String.

Model.java

import org.simreal.annotation.*;
import sim.engine.SimState;

@SimModel
public class Model extends SimState  {

    // rest of code

    @SimChart(name="chart_name")
    public int chartingMethod(){
        int result = 0;

        // perform operation to calculate and obtain integer representing ~
        // ~ aggregate simulation behaviour (update result)

        return result;
    }
}

Example of Charting Annotation Usage

Model.java

import org.simreal.annotation.*;
import sim.engine.SimState;
import sim.util.Bag;
import sim.util.IntBag;
import java.util.ArrayList;
import java.util.stream.Collectors;

@SimModel
public class Model extends SimState  {
    public static final long serialVersionUID = 1L;
    private int population;
    private Bag field;

    // rest of code

    public Model(@SimParam(value = "500") int population,
                 @SimParam(value = "100") int wealth) {
        super(System.currentTimeMillis());
        this.population = population;
    }

    // rest of code

    // define a charting method that calculates the total wealth of the top 10% ~
    // ~ wealthy population.
    @SimChart(name="top10")
    public int top10wealth(){
        // sort the bag of the population
        IntBag popln_wealth = new IntBag();
        // get the wealth in a intBag and sort it
        ((ArrayList<Agent>) field.stream().collect(Collectors.toList()))
            .forEach((agt_arg) -> {
                Agent agt = agt_arg;
                popln_wealth.add(agt.getWealth());
        });
        popln_wealth.sort();
        // get the sum of the top 10% wealth
        int top10_wealth_sum = 0;
        int top10_sz = (int) (population * 0.1);
        for(int i=population-top10_sz; i<population; i++){  
            top10_wealth_sum += popln_wealth.get(i);  
        }
        return top10_wealth_sum;
    }
}

In the above code snippet, the top10wealth method returns the wealth value of the top 10% the wealthiest agents in the Economy Model simulation (for more information see referenced model documentation). This value is received and charted on the MiniReal UI as shown below. The slider on the left can be used to narrow or widen the y-axis value range, hence zooming in or out of the chart.

Figure: Economy Model single chart visualization on MiniReal system.

Multiple Charts for a Simulation

It is possible to define multiple charts for a single simulation inorder to get various insights. This can be done by implementing multiple methods and annotating them with the @SimChart annotation. The name of the chart passed to the annotation, however, should be unique to each chart. The charts will be plt on the same grid differentiated by color.

Model.java

import org.simreal.annotation.*;
import sim.engine.SimState;
import sim.util.Bag;
import sim.util.IntBag;
import java.util.ArrayList;
import java.util.stream.Collectors;

@SimModel
public class Model extends SimState  {
    public static final long serialVersionUID = 1L;
    private int population;
    private Bag field;

    // rest of code

    public Model(@SimParam(value = "500") int population,
                 @SimParam(value = "100") int wealth) {
        super(System.currentTimeMillis());
        this.population = population;
    }

    // rest of code

    // define a charting method that calculates the total wealth of the top 10% ~
    // ~ wealthy population.
    @SimChart(name="top10")
    public int top10wealth(){
        // sort the bag of the population
        IntBag popln_wealth = new IntBag();
        // get the wealth in a intBag and sort it
        ((ArrayList<Agent>) field.stream().collect(Collectors.toList()))
            .forEach((agt_arg) -> {
                Agent agt = agt_arg;
                popln_wealth.add(agt.getWealth());
        });
        popln_wealth.sort();
        // get the sum of the top 10% wealth
        int top10_wealth_sum = 0;
        int top10_sz = (int) (population * 0.1);
        for(int i=population-top10_sz; i<population; i++){  
            top10_wealth_sum += popln_wealth.get(i);  
        }
        return top10_wealth_sum;
    }   

    // define a charting method that calculates the total wealth of the bottom ~
    // ~ 50% of the population in-terms of wealth.
    @SimChart(name="bottom50")
    public int bottom50wealth() {
        // sort the bag of the population
        IntBag popln_wealth = new IntBag();
        // get the wealth in a intBag and sort it
        ((ArrayList<Agent>) field.stream().collect(Collectors.toList()))
            .forEach((agt_arg) -> {
                Agent agt = agt_arg;
                popln_wealth.add(agt.getWealth());
        });
        popln_wealth.sort();
        // get the sum of the bootom 50% wealth
        int bottom50_wealth_sum = 0;
        int bottom50_sz = (int) (population * 0.5);
        for(int i=0; i<bottom50_sz; i++){   
            bottom50_wealth_sum += popln_wealth.get(i);  
        }
        return bottom50_wealth_sum;
    }
}

The result of running the above model is shown below. Users can enable or disable the display of each chart by clicking on the chart name.

Figure: Economy Model multiple charts visualization on MiniReal system.

Note

Inorder not to overload the UI and keep it responsive, the chart will be updated within few seconds. Thus at the start of the simulation, charts may not appear for few ticks.

Happy Modeling!