On Thu, Mar 5, 2009 at 8:53 PM, Jason Wolfe wrote:
>
>> The mutation constructing function seems obvious in hindsight. I feel
>> stupid now.
>
> You shouldn't :). Immutability definitely takes some getting used to;
> I know it's taking me quite some time to wrap my head around it.
I'm actually
> The mutation constructing function seems obvious in hindsight. I feel
> stupid now.
You shouldn't :). Immutability definitely takes some getting used to;
I know it's taking me quite some time to wrap my head around it.
-Jason
--~--~-~--~~~---~--~~
You receiv
On Thu, Mar 5, 2009 at 8:11 PM, Matt Moriarity wrote:
>
> what about memoizing the fitness function? call fitness on your
> structs, and if it's memoized, it will return the cached value as long
> as the struct is the same value. if it's changed, then it will
> recomput
utility function, which will make the change and also assoc on a new
fitness delay. In the simplest case, this would just be the
"constructor" for your individuals. (There's no reason to use
metadata unless you care about the equality semantics of
individuals.) This is the
what about memoizing the fitness function? call fitness on your
structs, and if it's memoized, it will return the cached value as long
as the struct is the same value. if it's changed, then it will
recompute. somebody correct me if this doesn't account for something,
but it sounds
Thanks for the advice, I never noticed delay existed!
It turns out I cannot put the fitness directly into the struct that
contains individuals. It would mean that every mutating function would
need to "reset" the fitness computation to avoid propagating a
misleading fitness and that
Hi,
Am 05.03.2009 um 10:13 schrieb bOR_:
Is there a reason why delay needs a force to be calculated?
delay creates a Delay object (Promise in Scheme). This can be
passed around like eg. a Vector. When you want to retrieve the
value, you have to use force, like get for a map. The first time
th
Didn't know of the existence of delay yet. Thanks for pointing that
out :).
Is there a reason why delay needs a force to be calculated?
> > > {:fitness (delay (compute-my-fitness))}
>
> > > And when you access the value use force.
>
> &g
blem; otherwise, probably
not.
user> (= (delay 2) (delay 2))
false
If this is the case, you probably want to store the delayed fitness
value as metadata on your individual:
(with-meta individual {:fitness (delay ...)})
(force (:fitness ^individual))
If you don't like delay/force, a
If you use hash-maps, or a struct-map as the basis of your individual,
you can just make a key 'fitness', and store the once-calculated
fitness in there.
I'm not sure how, but it might be possible that at the creation of
your animals, you assign the key 'fitness' a basic
Hi,
Am 04.03.2009 um 18:21 schrieb Dan:
How can I have my fitness computation be triggered on first access
and reused afterward?
Maybe you can use a Delay.
{:fitness (delay (compute-my-fitness))}
And when you access the value use force.
(-> my-thing :fitness force)
The first time
I am doing a genetic algorithm my individual have various immutable
characteristics, one of them being their fitness. The problem I have
with it is that fitness is somewhat expensive and can be requested
zero (the individual will undergo some transformation and the fitness
of the intermediary
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