More debugging and realizing how PHP does references

2025-11-04 10:12:28 +01:00 · 2010-09-25 15:46:23 -04:00
parent e8d444e7da
commit 086d94865f
21 changed files with 77 additions and 72 deletions
--- a/PHPSkills/FactorGraphs/Factor.php
+++ b/PHPSkills/FactorGraphs/Factor.php
@@ -36,12 +36,12 @@ abstract class Factor
        return count($this->_messages);
    }

-    protected function getVariables()
+    protected function &getVariables()
    {
        return $this->_variables;
    }

-    protected function getMessages()
+    protected function &getMessages()
    {
        return $this->_messages;
    }
@@ -77,11 +77,11 @@ abstract class Factor
        return $this->sendMessageVariable($message, $variable);
    }

-    protected abstract function sendMessageVariable(Message $message, Variable $variable);
+    protected abstract function sendMessageVariable(Message &$message, Variable &$variable);

-    public abstract function createVariableToMessageBinding(Variable $variable);
+    public abstract function createVariableToMessageBinding(Variable &$variable);

-    protected function createVariableToMessageBindingWithMessage(Variable $variable, Variable $message)
+    protected function createVariableToMessageBindingWithMessage(Variable &$variable, Variable &$message)
    {
        $index = count($this->_messages);
        $this->_messages[] = $message;
--- a/PHPSkills/FactorGraphs/FactorGraph.php
+++ b/PHPSkills/FactorGraphs/FactorGraph.php
@@ -5,14 +5,14 @@ class FactorGraph
 {
    private $_variableFactory;

-    public function getVariableFactory()
+    public function &getVariableFactory()
    {
        return $this->_variableFactory;
    }

-    public function setVariableFactory($factory)
+    public function setVariableFactory(&$factory)
    {
-        $this->_variableFactory = $factory;
+        $this->_variableFactory = &$factory;
    }
 }
 ?>
--- a/PHPSkills/FactorGraphs/FactorGraphLayer.php
+++ b/PHPSkills/FactorGraphs/FactorGraphLayer.php
@@ -1,6 +1,7 @@
 <?php
 namespace Moserware\Skills\FactorGraphs;

+require_once(dirname(__FILE__) . "/FactorGraph.php");
 require_once(dirname(__FILE__) . "/Schedule.php");

 abstract class FactorGraphLayer
@@ -10,44 +11,44 @@ abstract class FactorGraphLayer
    private $_inputVariablesGroups = array();
    private $_parentFactorGraph;

-    protected function __construct($parentGraph)
+    protected function __construct(FactorGraph &$parentGraph)
    {
-        $this->_parentFactorGraph = $parentGraph;
+        $this->_parentFactorGraph = &$parentGraph;
    }

-    protected function getInputVariablesGroups()
+    protected function &getInputVariablesGroups()
    {
        return $this->_inputVariablesGroups;        
    }

    // HACK

-    public function getParentFactorGraph()
+    public function &getParentFactorGraph()
    {
        return $this->_parentFactorGraph;
    }

-    public function getOutputVariablesGroups()
+    public function &getOutputVariablesGroups()
    {
        return $this->_outputVariablesGroups;        
    }

-    public function getLocalFactors()
+    public function &getLocalFactors()
    {
        return $this->_localFactors;        
    }

-    public function setInputVariablesGroups($value)
+    public function &setInputVariablesGroups(&$value)
    {
        $this->_inputVariablesGroups = $value;
    }

-    protected function scheduleSequence($itemsToSequence)
+    protected function scheduleSequence(&$itemsToSequence)
    {
        return new ScheduleSequence("TODO", $itemsToSequence);
    }

-    protected function addLayerFactor($factor)
+    protected function addLayerFactor(&$factor)
    {
        $this->_localFactors[] = $factor;
    }
--- a/PHPSkills/FactorGraphs/FactorList.php
+++ b/PHPSkills/FactorGraphs/FactorList.php
@@ -49,7 +49,7 @@ class FactorList
        return count($this->_list);
    }

-    public function addFactor(Factor $factor)
+    public function addFactor(Factor &$factor)
    {
        $this->_list[] = $factor;
        return $factor;
--- a/PHPSkills/FactorGraphs/Variable.php
+++ b/PHPSkills/FactorGraphs/Variable.php
@@ -14,12 +14,12 @@ class Variable
        $this->resetToPrior();
    }

-    public function getValue()
+    public function &getValue()
    {
        return $this->_value;
    }

-    public function setValue($value)
+    public function setValue(&$value)
    {
        $this->_value = $value;
    }
--- a/PHPSkills/SkillCalculator.php
+++ b/PHPSkills/SkillCalculator.php
@@ -14,7 +14,7 @@ abstract class SkillCalculator
    private $_playersPerTeamAllowed;
    private $_totalTeamsAllowed;
    
-    protected function __construct($supportedOptions, TeamsRange $totalTeamsAllowed, PlayersRange $playerPerTeamAllowed)
+    protected function __construct($supportedOptions, TeamsRange &$totalTeamsAllowed, PlayersRange &$playerPerTeamAllowed)
    {
        $this->_supportedOptions = $supportedOptions;
        $this->_totalTeamsAllowed = $totalTeamsAllowed;
@@ -29,7 +29,7 @@ abstract class SkillCalculator
    /// <param name="teams">A mapping of team players and their ratings.</param>
    /// <param name="teamRanks">The ranks of the teams where 1 is first place. For a tie, repeat the number (e.g. 1, 2, 2)</param>
    /// <returns>All the players and their new ratings.</returns>
-    public abstract function calculateNewRatings(GameInfo $gameInfo,
+    public abstract function calculateNewRatings(GameInfo &$gameInfo,
                                                 array $teamsOfPlayerToRatings,
                                                 array $teamRanks);

@@ -40,23 +40,23 @@ abstract class SkillCalculator
    /// <param name="gameInfo">Parameters for the game.</param>
    /// <param name="teams">A mapping of team players and their ratings.</param>
    /// <returns>The quality of the match between the teams as a percentage (0% = bad, 100% = well matched).</returns>
-    public abstract function calculateMatchQuality(GameInfo $gameInfo,
-                                                   array $teamsOfPlayerToRatings);
+    public abstract function calculateMatchQuality(GameInfo &$gameInfo,
+                                                   array &$teamsOfPlayerToRatings);

    public function isSupported($option)
    {           
        return ($this->_supportedOptions & $option) == $option;             
    }    

-    protected function validateTeamCountAndPlayersCountPerTeam(array $teamsOfPlayerToRatings)
+    protected function validateTeamCountAndPlayersCountPerTeam(array &$teamsOfPlayerToRatings)
    {
        self::validateTeamCountAndPlayersCountPerTeamWithRanges($teamsOfPlayerToRatings, $this->_totalTeamsAllowed, $this->_playersPerTeamAllowed);
    }

    private static function validateTeamCountAndPlayersCountPerTeamWithRanges(
-        array $teams,
-        TeamsRange $totalTeams, 
-        PlayersRange $playersPerTeam)
+        array &$teams,
+        TeamsRange &$totalTeams,
+        PlayersRange &$playersPerTeam)
    {        
        $countOfTeams = 0;
        
--- a/PHPSkills/TrueSkill/FactorGraphTrueSkillCalculator.php
+++ b/PHPSkills/TrueSkill/FactorGraphTrueSkillCalculator.php
@@ -40,7 +40,7 @@ class FactorGraphTrueSkillCalculator extends SkillCalculator
        parent::__construct(SkillCalculatorSupportedOptions::PARTIAL_PLAY | SkillCalculatorSupportedOptions::PARTIAL_UPDATE, TeamsRange::atLeast(2), PlayersRange::atLeast(1));
    }

-    public function calculateNewRatings(GameInfo $gameInfo,
+    public function calculateNewRatings(GameInfo &$gameInfo,
                                        array $teams,
                                        array $teamRanks)
    {
@@ -58,8 +58,8 @@ class FactorGraphTrueSkillCalculator extends SkillCalculator
        return $factorGraph->getUpdatedRatings();
    }

-    public function calculateMatchQuality(GameInfo $gameInfo,
-                                          array $teams)
+    public function calculateMatchQuality(GameInfo &$gameInfo,
+                                          array &$teams)
    {
        // We need to create the A matrix which is the player team assigments.
        $teamAssignmentsList = $teams;
@@ -100,7 +100,7 @@ class FactorGraphTrueSkillCalculator extends SkillCalculator
        return $result;
    }

-    private static function getPlayerMeansVector(array $teamAssignmentsList)
+    private static function getPlayerMeansVector(array &$teamAssignmentsList)
    {
        // A simple vector of all the player means.
        return new Vector($this->getPlayerRatingValues($teamAssignmentsList,
@@ -110,7 +110,7 @@ class FactorGraphTrueSkillCalculator extends SkillCalculator
                                                       }));
    }

-    private static function getPlayerCovarianceMatrix(array $teamAssignmentsList)
+    private static function getPlayerCovarianceMatrix(array &$teamAssignmentsList)
    {
        // This is a square matrix whose diagonal values represent the variance (square of standard deviation) of all
        // players.
@@ -123,7 +123,7 @@ class FactorGraphTrueSkillCalculator extends SkillCalculator
    }

    // Helper function that gets a list of values for all player ratings
-    private static function getPlayerRatingValues(array $teamAssignmentsList,
+    private static function getPlayerRatingValues(array &$teamAssignmentsList,
                                                  $playerRatingFunction)
    {
        $playerRatingValues = array();
@@ -139,7 +139,7 @@ class FactorGraphTrueSkillCalculator extends SkillCalculator
        return $playerRatingValues;
    }

-    private static function createPlayerTeamAssignmentMatrix($teamAssignmentsList, $totalPlayers)
+    private static function createPlayerTeamAssignmentMatrix(&$teamAssignmentsList, &$totalPlayers)
    {
        // The team assignment matrix is often referred to as the "A" matrix. It's a matrix whose rows represent the players
        // and the columns represent teams. At Matrix[row, column] represents that player[row] is on team[col]
--- a/PHPSkills/TrueSkill/Factors/GaussianFactor.php
+++ b/PHPSkills/TrueSkill/Factors/GaussianFactor.php
@@ -20,7 +20,7 @@ abstract class GaussianFactor extends Factor
    }

    /// Sends the factor-graph message with and returns the log-normalization constant
-    protected function sendMessageVariable(Message $message, Variable $variable)
+    protected function sendMessageVariable(Message &$message, Variable &$variable)
    {
        $marginal = $variable->getValue();
        $messageValue = $message->getValue();
@@ -29,7 +29,7 @@ abstract class GaussianFactor extends Factor
        return $logZ;
    }

-    public function createVariableToMessageBinding(Variable $variable)
+    public function createVariableToMessageBinding(Variable &$variable)
    {
        return parent::createVariableToMessageBinding($variable,
                                                      new Message(
--- a/PHPSkills/TrueSkill/Factors/GaussianGreaterThanFactor.php
+++ b/PHPSkills/TrueSkill/Factors/GaussianGreaterThanFactor.php
@@ -20,7 +20,7 @@ class GaussianGreaterThanFactor extends GaussianFactor
 {
    private $_epsilon;

-    public function __construct($epsilon, Variable $variable)
+    public function __construct($epsilon, Variable &$variable)
    {
        parent::_construct("{0} > {1:0.000}");
        $this->_epsilon = $epsilon;
@@ -42,7 +42,7 @@ class GaussianGreaterThanFactor extends GaussianFactor

    }

-    protected function updateMessageVariable(Message $message, Variable $variable)
+    protected function updateMessageVariable(Message &$message, Variable &$variable)
    {
        $oldMarginal = clone $variable->getValue();
        $oldMessage = clone $message->getValue();
--- a/PHPSkills/TrueSkill/Factors/GaussianLikelihoodFactor.php
+++ b/PHPSkills/TrueSkill/Factors/GaussianLikelihoodFactor.php
@@ -18,7 +18,7 @@ class GaussianLikelihoodFactor extends GaussianFactor
 {
    private $_precision;

-    public function __construct($betaSquared, Variable $variable1, Variable $variable2)
+    public function __construct($betaSquared, Variable &$variable1, Variable &$variable2)
    {
        parent::__construct("Likelihood of {0} going to {1}");
        $this->_precision = 1.0/$betaSquared;
@@ -36,8 +36,8 @@ class GaussianLikelihoodFactor extends GaussianFactor
                $messages[0]->getValue());
    }

-    private function updateHelper(Message $message1, Message $message2,
-                                  Variable $variable1, Variable $variable2)
+    private function updateHelper(Message &$message1, Message &$message2,
+                                  Variable &$variable1, Variable &$variable2)
    {
        $message1Value = clone $message1->getValue();
        $message2Value = clone $message2->getValue();
--- a/PHPSkills/TrueSkill/Factors/GaussianPriorFactor.php
+++ b/PHPSkills/TrueSkill/Factors/GaussianPriorFactor.php
@@ -19,7 +19,7 @@ class GaussianPriorFactor extends GaussianFactor
 {
    private $_newMessage;

-    public function __construct($mean, $variance, Variable $variable)
+    public function __construct($mean, $variance, Variable &$variable)
    {
        parent::__construct("Prior value going to {0}");
        $this->_newMessage = new GaussianDistribution($mean, sqrt($variance));
@@ -27,10 +27,10 @@ class GaussianPriorFactor extends GaussianFactor
                                               new Message(
                                                   GaussianDistribution::fromPrecisionMean(0, 0),
                                                       "message from {0} to {1}",
-                                                   this, variable));
+                                                   $this, variable));
    }

-    protected function updateMessageVariable(Message $message, Variable $variable)
+    protected function updateMessageVariable(Message &$message, Variable &$variable)
    {
        $oldMarginal = clone $variable->getValue();
        $oldMessage = $message;
--- a/PHPSkills/TrueSkill/Factors/GaussianWeightedSumFactor.php
+++ b/PHPSkills/TrueSkill/Factors/GaussianWeightedSumFactor.php
@@ -23,7 +23,7 @@ class GaussianWeightedSumFactor extends GaussianFactor
    private $_weights;
    private $_weightsSquared;

-    public function __construct(Variable $sumVariable, array $variablesToSum, array $variableWeights = null)
+    public function __construct(Variable &$sumVariable, array &$variablesToSum, array &$variableWeights = null)
    {
        parent::__construct($this->createName($sumVariable, $variablesToSum, $variableWeights));
        $this->_weights = array();
@@ -133,9 +133,9 @@ class GaussianWeightedSumFactor extends GaussianFactor
        return $result;
    }

-    private function updateHelper(array $weights, array $weightsSquared,
-                                  array $messages,
-                                  array $variables)
+    private function updateHelper(array &$weights, array &$weightsSquared,
+                                  array &$messages,
+                                  array &$variables)
    {
        // Potentially look at http://mathworld.wolfram.com/NormalSumDistribution.html for clues as
        // to what it's doing
--- a/PHPSkills/TrueSkill/Factors/GaussianWithinFactor.php
+++ b/PHPSkills/TrueSkill/Factors/GaussianWithinFactor.php
@@ -20,7 +20,7 @@ class GaussianWithinFactor extends GaussianFactor
 {
    private $_epsilon;

-    public function __construct($epsilon, Variable $variable)
+    public function __construct($epsilon, Variable &$variable)
    {
        $this->_epsilon = $epsilon;
        $this->createVariableToMessageBinding($variable);
@@ -43,7 +43,7 @@ class GaussianWithinFactor extends GaussianFactor
        return -GaussianDistribution::logProductNormalization($messageFromVariable, $message) + log($z);
    }

-    protected function updateMessage(Message $message, Variable $variable)
+    protected function updateMessage(Message &$message, Variable &$variable)
    {
        $oldMarginal = clone $variable->getValue();
        $oldMessage = clone $message->getValue();
--- a/PHPSkills/TrueSkill/Layers/IteratedTeamDifferencesInnerLayer.php
+++ b/PHPSkills/TrueSkill/Layers/IteratedTeamDifferencesInnerLayer.php
@@ -18,9 +18,9 @@ class IteratedTeamDifferencesInnerLayer extends TrueSkillFactorGraphLayer
    private $_TeamDifferencesComparisonLayer;
    private $_TeamPerformancesToTeamPerformanceDifferencesLayer;

-    public function __construct(TrueSkillFactorGraph $parentGraph,
-                                TeamPerformancesToTeamPerformanceDifferencesLayer $teamPerformancesToPerformanceDifferences,
-                                TeamDifferencesComparisonLayer $teamDifferencesComparisonLayer)
+    public function __construct(TrueSkillFactorGraph &$parentGraph,
+                                TeamPerformancesToTeamPerformanceDifferencesLayer &$teamPerformancesToPerformanceDifferences,
+                                TeamDifferencesComparisonLayer &$teamDifferencesComparisonLayer)
    {
        parent::__construct($parentGraph);
        $this->_TeamPerformancesToTeamPerformanceDifferencesLayer = $teamPerformancesToPerformanceDifferences;
--- a/PHPSkills/TrueSkill/Layers/PlayerPerformancesToTeamPerformancesLayer.php
+++ b/PHPSkills/TrueSkill/Layers/PlayerPerformancesToTeamPerformancesLayer.php
@@ -14,7 +14,7 @@ use Moserware\Skills\TrueSkill\TrueSkillFactorGraph;

 class PlayerPerformancesToTeamPerformancesLayer extends TrueSkillFactorGraphLayer
 {
-    public function __construct(TrueSkillFactorGraph $parentGraph)
+    public function __construct(TrueSkillFactorGraph &$parentGraph)
    {
        parent::__construct($parentGraph);
    }
@@ -44,7 +44,7 @@ class PlayerPerformancesToTeamPerformancesLayer extends TrueSkillFactorGraphLaye
                "all player perf to team perf schedule");
    }

-    protected function createPlayerToTeamSumFactor($teamMembers, $sumVariable)
+    protected function createPlayerToTeamSumFactor(&$teamMembers, &$sumVariable)
    {
        return new GaussianWeightedSumFactor(
                $sumVariable,
@@ -74,7 +74,7 @@ class PlayerPerformancesToTeamPerformancesLayer extends TrueSkillFactorGraphLaye
        return $this->scheduleSequence($allFactors, "all of the team's sum iterations");
    }

-    private function createOutputVariable($team)
+    private function createOutputVariable(&$team)
    {
        ///$teamMemberNames = String.Join(", ", team.Select(teamMember => teamMember.Key.ToString()).ToArray());
        $teamMemberNames = "TODO";
--- a/PHPSkills/TrueSkill/Layers/PlayerPriorValuesToSkillsLayer.php
+++ b/PHPSkills/TrueSkill/Layers/PlayerPriorValuesToSkillsLayer.php
@@ -19,7 +19,7 @@ class PlayerPriorValuesToSkillsLayer extends TrueSkillFactorGraphLayer
 {
    private $_teams;

-    public function __construct(TrueSkillFactorGraph $parentGraph, $teams)
+    public function __construct(TrueSkillFactorGraph &$parentGraph, &$teams)
    {
        parent::__construct($parentGraph);
        $this->_teams = $teams;
@@ -31,10 +31,11 @@ class PlayerPriorValuesToSkillsLayer extends TrueSkillFactorGraphLayer
        {
            $currentTeamSkills = array();

-            foreach ($currentTeam as $currentTeamPlayer)
+            foreach ($currentTeam->getAllPlayers() as $currentTeamPlayer)
            {
-                $playerSkill = $this->createSkillOutputVariable($currentTeamPlayer.Key);
-                $this->addLayerFactor($this->createPriorFactor($currentTeamPlayer.Key, $currentTeamPlayer.Value, $playerSkill));
+                $currentTeamPlayerRating = $currentTeam->getRating($currentTeamPlayer);
+                $playerSkill = $this->createSkillOutputVariable($currentTeamPlayer);
+                $this->addLayerFactor($this->createPriorFactor($currentTeamPlayer, $currentTeamPlayerRating, $playerSkill));
                $currentTeamSkills[] = $playerSkill;
            }

@@ -55,7 +56,7 @@ class PlayerPriorValuesToSkillsLayer extends TrueSkillFactorGraphLayer
                 "All priors");
    }

-    private function createPriorFactor($player, $priorRating, $skillsVariable)
+    private function createPriorFactor(&$player, &$priorRating, &$skillsVariable)
    {
        return new GaussianPriorFactor($priorRating->getMean(),
                                       square($priorRating->getStandardDeviation()) +
@@ -65,7 +66,9 @@ class PlayerPriorValuesToSkillsLayer extends TrueSkillFactorGraphLayer

    private function createSkillOutputVariable($key)
    {
-        return $this->getParentFactorGraph()->getVariableFactory()->createKeyedVariable($key, "{0}'s skill", $key);
+        $parentFactorGraph = $this->getParentFactorGraph();
+        $variableFactory = $parentFactorGraph->getVariableFactory();
+        return $variableFactory->createKeyedVariable($key, "{0}'s skill", $key);
    }
 }

--- a/PHPSkills/TrueSkill/Layers/PlayerSkillsToPerformancesLayer.php
+++ b/PHPSkills/TrueSkill/Layers/PlayerSkillsToPerformancesLayer.php
@@ -13,7 +13,7 @@ use Moserware\Skills\TrueSkill\Factors\GaussianLikelihoodFactor;

 class PlayerSkillsToPerformancesLayer extends TrueSkillFactorGraphLayer
 {
-    public function __construct(TrueSkillFactorGraph $parentGraph)
+    public function __construct(TrueSkillFactorGraph &$parentGraph)
    {
        parent::__construct($parentGraph);
    }
@@ -36,12 +36,12 @@ class PlayerSkillsToPerformancesLayer extends TrueSkillFactorGraphLayer
        }
    }

-    private function createLikelihood($playerSkill, $playerPerformance)
+    private function createLikelihood(&$playerSkill, &$playerPerformance)
    {
        return new GaussianLikelihoodFactor(square($this->getParentFactorGraph()->getGameInfo()->getBeta()), $playerPerformance, $playerSkill);
    }

-    private function createOutputVariable($key)
+    private function createOutputVariable(&$key)
    {
        return $this->getParentFactorGraph()->getVariableFactory()->createKeyedVariable($key, "{0}'s performance", $key);
    }
--- a/PHPSkills/TrueSkill/Layers/TeamDifferencesComparisonLayer.php
+++ b/PHPSkills/TrueSkill/Layers/TeamDifferencesComparisonLayer.php
@@ -17,7 +17,7 @@ class TeamDifferencesComparisonLayer extends TrueSkillFactorGraphLayer
    private $_epsilon;
    private $_teamRanks;

-    public function __construct(TrueSkillFactorGraph $parentGraph, array $teamRanks)
+    public function __construct(TrueSkillFactorGraph &$parentGraph, array &$teamRanks)
    {
        parent::__construct($parentGraph);
        $this->_teamRanks = $teamRanks;
--- a/PHPSkills/TrueSkill/Layers/TeamPerformancesToTeamPerformanceDifferencesLayer.php
+++ b/PHPSkills/TrueSkill/Layers/TeamPerformancesToTeamPerformanceDifferencesLayer.php
@@ -13,7 +13,7 @@ use Moserware\Skills\TrueSkill\Factors\GaussianWeightedSumFactor;

 class TeamPerformancesToTeamPerformanceDifferencesLayer extends TrueSkillFactorGraphLayer
 {
-    public function __construct(TrueSkillFactorGraph $parentGraph)
+    public function __construct(TrueSkillFactorGraph &$parentGraph)
    {
        parent::__construct($parentGraph);
    }
@@ -38,7 +38,7 @@ class TeamPerformancesToTeamPerformanceDifferencesLayer extends TrueSkillFactorG
    }

    private function createTeamPerformanceToDifferenceFactor(
-        Variable $strongerTeam, Variable $weakerTeam, Variable $output)
+        Variable &$strongerTeam, Variable &$weakerTeam, Variable &$output)
    {
        return new GaussianWeightedSumFactor($output, array($strongerTeam, $weakerTeam), array(1.0, -1.0));
    }
--- a/PHPSkills/TrueSkill/Layers/TrueSkillFactorGraphLayer.php
+++ b/PHPSkills/TrueSkill/Layers/TrueSkillFactorGraphLayer.php
@@ -9,7 +9,7 @@ use Moserware\Skills\TrueSkill\TrueSkillFactorGraph;

 abstract class TrueSkillFactorGraphLayer extends FactorGraphLayer
 {
-    public function __construct(TrueSkillFactorGraph $parentGraph)
+    public function __construct(TrueSkillFactorGraph &$parentGraph)
    {
        parent::__construct($parentGraph);
    }
--- a/PHPSkills/TrueSkill/TrueSkillFactorGraph.php
+++ b/PHPSkills/TrueSkill/TrueSkillFactorGraph.php
@@ -35,15 +35,16 @@ class TrueSkillFactorGraph extends FactorGraph
    private $_priorLayer;
    private $_variableFactory;

-    public function __construct(GameInfo $gameInfo, $teams, array $teamRanks)
+    public function __construct(GameInfo &$gameInfo, &$teams, array $teamRanks)
    {
        $this->_priorLayer = new PlayerPriorValuesToSkillsLayer($this, $teams);
        $this->_gameInfo = $gameInfo;
-        $this->_variableFactory = new VariableFactory(
+        $newFactory = new VariableFactory(
                                        function()
                                        {
                                            return GaussianDistribution::fromPrecisionMean(0, 0);
                                        });
+        $this->setVariableFactory($newFactory);

        $this->_layers = array(
                              $this->_priorLayer,