Re: Particle Swarm Optimization

anton@[EMAIL PROTECTED]
 (Anton Ertl) writes Re: Particle Swarm
Optimization
[..]
> mhx@[EMAIL PROTECTED]
 (Marcel Hendrix) writes:
>>anton@[EMAIL PROTECTED]
 (Anton Ertl) writes Re: Particle Swarm
Optimization
[..]
>>Well, ant algorithms can solve 'discrete' problems (without 
>>derivatives) which is useful. AFAIK, particle swarms can't 
>>handle such discrete problems, and are very bad at accurately 
>>finding derivatives.

> Ok.  I was not looking at the algorithms in such detail.  It just
> seems to me that, as soon as the first ant or particle hits a (local)
> optimum, 

How would they know it was an optimum?

>          the others are unnecessary for finding that optimum, and
> these algorithms also don't seem to provide a useful way to get out of
> the local optimum and find another one.

Well, they find another because they "like" a good solution found
by fellow ants, but always keep doing a little independent exploring 
on the side. The balance between 'following the herd' and 'reinventing
the wheel' is of course very critical. (Now, why does that sound so 
familiar?) Simulated annealing takes this a step further by allowing 
very independent searching in the first iterations, gradually stifling 
free spirits when time progresses :-)

[ structs ]
> What I meant was: Had this package been known to be widely used a year
> or two ago, it may have had a good chance to be standardized in
> Forth200x.

Well, I became interested in January 2005, when I needed it for my
circuit simulators and my online bank account tracker. I am not 
really overjoyed having to change the syntax.

>>Would the following be close enough 
>>for Forth 200x? I think the word +FIELD can be combined with 
[..]

> I don't think that this is a correct implementation of Forth200x
> X:structures, because it requires that there is the alignment on the
> stack.  E.g., code like this would not work:

> 0
>  cfield: x
>  field:  y
> constant xy

I was hoping people would use the provided BEGIN-STRUCTURE and 
END-STRUCTURE :-)

-marcel