Tony, it's not too tough at all.  All you need is a function which  
picks a random interval of time based on your probabilistic  
distribution.  Then in the agent's step() method, the first thing you  
say something like:

	double delta = random_interval_of_time();
	state.schedule.scheduleOnceIn(delta, this);

And you're done!  If you want a more abstract thing, we can put  
together a class which does arbitrary repeats.  Like Repast, you can  
also replace or subclass MASON's schedule.  For example, we could  
modify the Repeat inner class to call a function in Schedule to get  
the interval to step by rather than a fixed interval, and then you  
just override that function to provide the interval you like.

Sean

On Jun 30, 2011, at 1:54 PM, Tony Bigbee wrote:

> Hi,
>
> There may only be one or two MASON core team members on this list  
> who can answer this question, but:
>
> I've inherited some code in an internal project that uses a  
> subclassed AbstractAction from Repast so that things are stepped  
> according to a probabilistic distribution--instead of stepping at  
> precise intervals, such as every 10 ticks, scheduled entities are  
> stepped, on average, every 10 ticks:
>
> "GeomAction provides an IAction that repeats at intervals drawn from  
> the geometric distribution.  The interval parameter passed into the  
> constructor is the probability that the action occurs in one  
> tick.The event [AbstractAction] converts the interval to log(1-P) to  
> increase efficiency in computing the interval.  The interval for  
> rescheduling will be ceiling(log(U)/log(1-P)) where U is a draw from  
> the uniform random distribution between 0 and 1.0"
>
> Repast allows you to replace their "schedule" with a custom version,  
> and ours creates GeomAction instances as described above.  They use  
> reflection and annotated methods rather than a step() approach like  
> MASON, but that's not the important part of this.
>
> Is geometric scheduling would be something that I could implement in  
> MASON and what the scope might entail?  I would like to consider  
> switching our project to MASON.