Re: Where and how to create probe maps?

[glen e. p. ropella]

> I'm wondering where to create them.  In the example applications, the probe
> maps are all created by the observerSwarm, which sort of makes sense, since
> the probe maps aren't really part of the model per se.  On the other hand,
> it seems like this requires the observerSwarm to be edited each time an
> agent is changed or a subclass of agent added, which doesn't seem very
> clean.
> 
> I thought I might define a createProbeMap method for each agent subclass,
> which has the advantage that it at least puts the various lists of
> variables in the same file.  However, I still have to edit the
> observerSwarm to call all these new createProbeMaps methods.  Also, I want
> to call the method before there are any instances of the class, so it would
> seem that createProbeMap has to be a class method.
> 
> Is there a better way?

Kevin,

This is either a style issue or a filosofickle issue.  There is a
clear precedent for creating them in the ObserverSwarm.  But, what you
may not know is that there is also a precedent for creating them in
the object class (like you suggest with a "createProbeMap" method).
However, as you point out, since it really is a class-wide probe map,
it's probably not wise to make it an instance method, which is what I
did.

Probes were really designed for probing objects from the outside
without forcing the user to put methods in each object class
specifically related to getting at the state and messages of the
object.

However! There is the issue of generic data transfer from one object
to another.  I was thinking of probes as precursors to data pipes or
channels from one object to the next.  It turns out there are problems
with this view and we will probably begin thinking about how we can
fit a data-flow methodology into Swarm.  This might also help us in
our data output formatting and interfacing with GIS, statistical, and
visualization packages.

So, the at the end of my little sojourn, here, I'd have to say that
the probe map for a class should probably be designed outside of the
class, itself.  Now, whether one puts it in a Swarm (Observer or
Model) or, as Barry has suggested, a User-Interface Object, is another
story.

Any thoughts?

glen