[Freeciv-Dev] Re: Unit-vs-stack sim (was: Cache win_chance)

[Gregory Berkolaiko <gberkolaiko@xxxxxxxxxxx>]

 --- Raimar Falke <hawk@xxxxxxxxxxxxxxxxxxxxxxx> wrote: 
> On Sat, Feb 23, 2002 at 04:45:46PM +0000, Gregory Berkolaiko wrote:
> 
> > Now let's identify the needs: precisely what information are we seeking
> > from
> > this potentially very complicated simulation?  How are we going to use it?
> > [remains to be filled in]
> 
> I think I have described this.

Mmm, not well enough I am afraid

> > 1. Outcome of one attack is already a complicated thing: besides won/lost
> > distribution we have a much wider distribution of the remaining health of
> > the
> > winner.  It is not hard to compute (it's done in win_chance) but should it
> > be
> > stored and used?  Or just a conditional mean(*) would do?
> 
> This simulation function will not anything in struct unit. It will
> store things in the result structure (comres).

I am not sure why you say this...  Isn't it obvious?

> Yes the health loss of the units have to be considered. But I see no
> problem in tracking them.

On the average -- no problem.  But is average good enough for you?
And you didn't take it into account in the example you considered

> 
> > 2. Outcome of one attack will be affecting the next attack.  If it ever
> > happens, because we have one more branch here: what if the defender
> > decides to attack us?
> > 3. More branching will follow: what if reinforcements arrive to the city
> > we
> > are sacking?
> 
> We don't know what happens next (neither with the next packet of the
> enemy to the server nor in the next turn). This is a simple
> function. There will be no intelligence in it.

but you did multiple attacks.  for most units you'd need more than one turn to
do that.

> > The present AI follows a very simple (thus unsatisfactory for some of us)
> > mathematical principle: step-by-step maximization.  AI takes an action if
> > on
> > average it would be better off after this action (apart from the broken
> > auto-attack which I will fix as soon as Raahul supplies me with the
> > promised
> > savegame).
> 
> How well does it handle unit stacks? Example: pdef1 is a good
> defender, pdef2 is an expensive unit, pdef3 is a cheap one. All in a
> fortress. The attacker will likely destroy pdef1, will also destory
> pdef2 and but will be destroyed by pdef3.

What is your question here?

> > But maybe we can come up with the algorithm which would go into sufficient
> > depth for you and be sufficiently simple for my small brain.  So let's
> > discuss.
> 
> I'm now not concerned about problems of the implementation (hp and
> veteran tracking) but about the interface. The proposed interface
> would wrt to my current knowledge be necessary to start coding any
> military agents. But will this interface also be good enough to be a
> help for the server AI?

the simulation that IMO is useful to AI is:  what will happen between now and
next turn.  The decision tree (can be much expanded).

(1)     attack
       /      \
    died      alive
                |
              has moves?
             /         \
        goto end        what will we do next?
                     /         |        |      \      
                 run away    attack    rest    occupy city
                    |          |        |          |
                 goto end    goto(1)  goto end  goto end

(end) consider possible enemy reprisals until the next turn comes

The end result would be sturcture with all branches and their probs, list of
dead units and cities and the resulting HP and status alterations.
So very much like yours :)

But I don't think it will be very practical.

Ufff, art is so demanding...

Best,
G.

P.S. I think I misunderstood your proposal.  I thought you want to simulate
further than one turn.

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