trueskill/PHPSkills/TrueSkill/Layers/TeamPerformancesToTeamPerformanceDifferencesLayer.php
2010-09-30 08:25:31 -04:00

56 lines
2.1 KiB
PHP

<?php
namespace Moserware\Skills\TrueSkill\Layers;
require_once(dirname(__FILE__) . "/../../FactorGraphs/Variable.php");
require_once(dirname(__FILE__) . "/../TrueSkillFactorGraph.php");
require_once(dirname(__FILE__) . "/../Factors/GaussianWeightedSumFactor.php");
require_once(dirname(__FILE__) . "/TrueSkillFactorGraphLayer.php");
use Moserware\Skills\FactorGraphs\Variable;
use Moserware\Skills\TrueSkill\DrawMargin;
use Moserware\Skills\TrueSkill\TrueSkillFactorGraph;
use Moserware\Skills\TrueSkill\Factors\GaussianWeightedSumFactor;
class TeamPerformancesToTeamPerformanceDifferencesLayer extends TrueSkillFactorGraphLayer
{
public function __construct(TrueSkillFactorGraph &$parentGraph)
{
parent::__construct($parentGraph);
}
public function buildLayer()
{
$inputVariablesGroups = &$this->getInputVariablesGroups();
$inputVariablesGroupsCount = count($inputVariablesGroups);
$outputVariablesGroup = &$this->getOutputVariablesGroups();
for ($i = 0; $i < $inputVariablesGroupsCount - 1; $i++)
{
$strongerTeam = &$inputVariablesGroups[$i][0];
$weakerTeam = &$inputVariablesGroups[$i + 1][0];
$currentDifference = &$this->createOutputVariable();
$newDifferencesFactor = $this->createTeamPerformanceToDifferenceFactor($strongerTeam, $weakerTeam, $currentDifference);
$this->addLayerFactor($newDifferencesFactor);
// REVIEW: Does it make sense to have groups of one?
$outputVariablesGroup[] = array($currentDifference);
}
}
private function createTeamPerformanceToDifferenceFactor(
Variable &$strongerTeam, Variable &$weakerTeam, Variable &$output)
{
$teams = array($strongerTeam, $weakerTeam);
$weights = array(1.0, -1.0);
return new GaussianWeightedSumFactor($output, $teams, $weights);
}
private function createOutputVariable()
{
return $this->getParentFactorGraph()->getVariableFactory()->createBasicVariable("Team performance difference");
}
}
?>