Difference between revisions of "Initialisation"

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(Basic APS)
(Population cost)
 
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== Basic APS ==
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== Basic initialisation (i0) ==
 
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[[Image:Basic APS N vs D.png|right|thumb|400px|Population size vs Dimension]]
 
Draw at random $N$ agents (positions) in the search space, according to an uniform distribution.
 
Draw at random $N$ agents (positions) in the search space, according to an uniform distribution.
  
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where $D$ is the dimension of the search space. Note that $N$ needs to be at least equal to $D+1$.
 
where $D$ is the dimension of the search space. Note that $N$ needs to be at least equal to $D+1$.
  
[[File:Basic APS N vs D.png|center]]
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We will need the volume $V(0)$ of the previous simplex. As no one has been defined yet, we simply set it to 0:<br />
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$$V(0)=0$$
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=== Population cost ===
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Evaluate the $N$ individuals, thanks to the function $f$ we are studying. Save the best one as $Best$.
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The sum of all values (they are all supposed to be positive, which is always possible), is the initial ''population cost'' $C$. We are trying here to minimise it.

Latest revision as of 17:55, 28 June 2013

Basic initialisation (i0)

Population size vs Dimension

Draw at random $N$ agents (positions) in the search space, according to an uniform distribution.

$N=\max\left(40+2\sqrt{D},\sqrt{40^{2}+\left(D+2\right)^{2}}\right)\tag{1}$

where $D$ is the dimension of the search space. Note that $N$ needs to be at least equal to $D+1$.

We will need the volume $V(0)$ of the previous simplex. As no one has been defined yet, we simply set it to 0:
$$V(0)=0$$

Population cost

Evaluate the $N$ individuals, thanks to the function $f$ we are studying. Save the best one as $Best$.

The sum of all values (they are all supposed to be positive, which is always possible), is the initial population cost $C$. We are trying here to minimise it.