[Repast-developer] Re: hiding the schedule

[Nick C. <ni...@sr...>]

Thanks for the feedback. I've attached a new version with the shuffling
in place. This does raise questions about how you want to handle the
random seed, however.

Nick

On Thu, 2001-09-06 at 19:29, Laszlo Gulyas wrote:
> Hi,
> 
> First of all, I liked the SimpleModel class pretty much, so thanks for the 
> good work.
> I'll give it some more thoughts during the coming days, though...
> 
> At this point, the only thing which came up was the scrambling of the
> agentList before each autoStep, in order to have the order in which the
> agents are called randomized. I wonder whether this should also be automated.
> I understand that you could do that in preStep(), but may be, having a flag 
> for that,
> too would be even easier.
> 
> Best,
> 
> Gulya
> 
> 
> At 02:42 PM 9/6/01 -0400, Nick Collier wrote:
> >Hi,
> >
> >I've attached the first cut of a base model class that attempts to hide 
> >the scheduling mechanism. (For those of you tuning in late, this is for 
> >teaching purposes although its probably applicable to a lot of current 
> >models as well). Its based on the tutorial TemplateModel by Lars-Erik and 
> >Gulya. The idea here is that the user subclasses SimpleModel and 
> >implements or overrides a few methods while SimpleModel takes care of the 
> >scheduling.
> >
> >The important pieces here are:
> >
> >1. The run*(), and *step() methods. The idea here is to split up the 
> >behavoir executed each tick into pre (preStep()), post (postStep()), and 
> >executing (step()) phases. So in the case of a cooperation game, the user 
> >would override the step() method to have the agents play the game, and the 
> >preStep() and postStep() would do any necessary prepartion or destruction. 
> >What actually executes each tick is preStep(), step() and then postStep().
> >
> >If autoStep is set to true, SimpleModel will execute the preStep(), 
> >autoStep() and then postStep(). autoStep() loops through the agent list 
> >calling step on each agent. For this to work the agents must implement the 
> >Stepable interface.
> >
> >2. The stopping time stuff. This was in the TemplateModel code so I 
> >assumed it was important and implemented it. The idea here is that the 
> >user can set the stopping time via a call to setStoppingTime in their 
> >model, and SimpleModel will schedule the model to stop when that tick has 
> >completed.
> >
> >So, is this enough? Do we need to include some random number 
> >initialization? Should SimpleModel be abstract and force people to 
> >implement buildModel()? Any other thoughts, comments, etc. are of course 
> >welcome.
> >
> >Nick
> >
> >
> >Lars-Erik Cederman wrote:
> >>Nick: This sounds like music to our ears! When do you think you might be 
> >>done with this new version? Gulya and I will be teaching RePast as of 
> >>October and we're obviously very keen to have a standardized hiding mechanism.
> >>We'd be more than happy to contribute ideas and code so that we can get 
> >>this one up and running very soon.
> >>I should mention that Gulya has now arrived in Cambridge. His email 
> >>address is gu...@la....
> >>Cheers, L-E
> >>
> >>
> >>>Hi,
> >>>
> >>>I'm thinking for the next release of repast I'll add something along the 
> >>>lines of your tutorial model that hides the scheduler, and assumes a 
> >>>step method in the agents. I'd appreciate your thoughts on this.
> >>>
> >>>thanks,
> >>>
> >>>Nick
> >>>
> >>>--
> >>>Nick Collier
> >>>Social Science Research Computing
> >>>University of Chicago
> >>>http://repast.sourceforge.net
> >>
> >
> >
> >--
> >Nick Collier
> >Social Science Research Computing
> >University of Chicago
> >http://repast.sourceforge.net
> >
> >
> >
> >package uchicago.src.sim.engine;
> >
> >public interface Stepable {
> >
> >   public void step();
> >
> >}
> >package uchicago.src.sim.engine;
> >
> >import java.util.ArrayList;
> >
> >public class SimpleModel extends SimModelImpl {
> >
> >   protected Schedule schedule;
> >   protected ArrayList agentList;
> >   protected String name = "A RePast Model";
> >   protected String[] params = {""};
> >   private long stoppingTime = -1;
> >   private BasicAction stoppingAction;
> >   protected boolean autoStep = false;
> >
> >   public void setStoppingTime(int time) {
> >     stoppingTime = time;
> >     if (stoppingAction != null) schedule.removeAction(stoppingAction);
> >     if (schedule != null) setStopAction();
> >   }
> >
> >   private void setStopAction() {
> >     System.out.println(stoppingTime);
> >     schedule.scheduleActionAt(stoppingTime, this,"stop", Schedule.LAST);
> >   }
> >
> >   public void setup() {
> >     stoppingTime = -1;
> >     stoppingAction = null;
> >     schedule = new Schedule();
> >     agentList = new ArrayList();
> >   }
> >
> >   public void begin() {
> >     buildModel();
> >     buildSchedule();
> >   }
> >
> >   public String getName() {
> >     return name;
> >   }
> >
> >   public Schedule getSchedule() {
> >     return schedule;
> >   }
> >
> >   public String[] getInitParam() {
> >     return params;
> >   }
> >
> >   public void buildModel() {}
> >
> >   public void buildSchedule() {
> >     if (autoStep) schedule.scheduleActionBeginning(1, this, "runAutoStep");
> >     else schedule.scheduleActionBeginning(1, this, "run");
> >     setStopAction();
> >   }
> >
> >   public void runAutoStep() {
> >     preStep();
> >     autoStep();
> >     postStep();
> >   }
> >
> >   public void run() {
> >     preStep();
> >     step();
> >     postStep();
> >   }
> >
> >   private void autoStep() {
> >     int size = agentList.size();
> >     for (int i = 0;i < size; i++) {
> >       Stepable agent = (Stepable)agentList.get(i);
> >       agent.step();
> >     }
> >   }
> >
> >   protected void preStep() {}
> >   protected void step() {}
> >   protected void postStep() {}
> >
> >   public static void main(String[] args) {
> >     SimInit init = new SimInit();
> >     SimpleModel model = new SimpleModel();
> >     if (args.length > 0) init.loadModel(model, args[0], false);
> >     else init.loadModel(model, null, false);
> >   }
> >
> >}
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> 
> --
> Laszlo Gulyas, MSc
> Government Department   Weatherhead Center for International Affairs
> Harvard University              602C Coolidge Hall
> 1737 Cambridge street           Cambridge, MA-02138
> 
> 
-- 
Nick Collier 
Social Science Research Computing
University of Chicago 
http://repast.sourceforge.net