Re: Scheduling question

[Roger M. Burkhart]

Sven Thommesen originally asked:

> I have 3 types of agents, each managed by an agent swarm created by and
> owned by the modelSwarm.
> 
> The agent swarms are activated in the modelSwarm one after the other, which
> means all agents of one type perform all their 'step' activities before
> agents of the next type go.
> 
> I'd now like to split up the agent 'step' activities into substeps, and
> have all 3 agent types do 'step#1' before they all get to do 'step#2'. 
> 
> How do I arrange scheduling to achieve this ? Is it possible to activate a
> sub-activity of a swarm in the owner swarm, or do I have to move all
> activation stuff up into the modelSwarm?

and then answered Marcus's question:

> >Would you first explain why it is useful to have a different Swarm for
> >different agent types?
> 
> It seemed the ... orderly thing to do. Compartmentalization works. Objects
> are good. (It is not *required* by my app, if that's what you are asking.)
> 
> I'm aware that I could solve my conundrum by pulling code back from the
> agent swarms together into the modelswarm. Doing so would require a bit of
> re-programming. 
> 
> I was just wondering if there is some wrinkle to using the scheduling
> machinery that I don't know about that would solve the problem in some
> other way.

Splitting agent populations into subswarms is certainly part of the Swarm
design philosophy, but the sub-populations would ordinarily defined as part
of some structure of interaction within the model rather that just agent
types.

But to answer the narrow question about splitting up "step" actions: if the
actions are all really scheduled at the same time value, then to the model
they really are concurrent and subject only to the sequencing rules declared
for actions at the same time step.  Right now, this is only to run them in
the order in which they were originally scheduled, or in which they were
activated within a containing swarm.  As you note, this does give you control
over what order the step actions are to be performed in, but not to divide
them into substeps at the same time value.

If you want this degree of subdivision within a larger time window, the
simplest solution would be merely to split your units of time into some
finer division, and schedule all of the first step actions into a time unit
on a first beat of your time clock and all of the second step actions onto a
second beat, just to put some rhythm into your schedules.  You just have to
be aware that this use of this clock value is purely artificial to get the
special syncopated timing you want to perform.

The complicated solution would be the ability to specify a custom "Concurrent
Group Type" that you declare when you initialize a swarm, and that would
interpret all concurrently scheduled actions from any subschedule to run
in any manner that the concurrent group type imposes.  This mechanism is
currently used internally by the scheduling machinery (for example, to
sequence subswarms of a containing swarm to run in order of activation, when
they happen to be scheduled on the time step).  It has a fairly complex
internal interface, however, and is not currently documented for end-user
use.

The intent of concurrent groups is to provide a special handler to resolve
conflict in the special case of actions that get scheduled to run
concurrently even though they might otherwise run individually.  They seem
like they'd be overkill to merely schedule actions that always occur in a
completely repeatable sequence.  If you want to trigger step actions on your
agents by type, you might just create three separate collections of the
agents by type (instead of full swarms) and then schedule three "foreach"
initial step actions on these collections followed by three followup actions
to complete the step by type.

--Roger
  

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