Tenative pass at getting prior layer working. Found out about division by zero and closure differences.

PHPSkills/FactorGraphs/Factor.php

@@ -9,7 +9,6 @@ require_once(dirname(__FILE__) . "/Variable.php");
 use Moserware\Skills\Guard;
 use Moserware\Skills\HashMap;
 
-
 abstract class Factor
 {
     private $_messages = array();
@@ -21,7 +20,7 @@ abstract class Factor
     protected function __construct($name)
     {
         $this->_name = "Factor[" . $name . "]";
-        $this->_messagesToVariableBinding = new HashMap();
+        $this->_messageToVariableBinding = new HashMap();
     }
 
     /// Returns the log-normalization constant of that factor
@@ -81,12 +80,12 @@ abstract class Factor
 
     public abstract function createVariableToMessageBinding(Variable &$variable);
 
-    protected function createVariableToMessageBindingWithMessage(Variable &$variable, Variable &$message)
+    protected function createVariableToMessageBindingWithMessage(Variable &$variable, Message &$message)
     {
         $index = count($this->_messages);
-        $this->_messages[] = $message;
+        $this->_messages[] = $message;        
         $this->_messageToVariableBinding->setValue($message, $variable);
-        $this->_variables[] = $variable;
+        $this->_variables[] = &$variable;
         return $message;
     }
 

PHPSkills/FactorGraphs/FactorGraphLayer.php

@@ -38,7 +38,7 @@ abstract class FactorGraphLayer
         return $this->_localFactors;        
     }
 
-    public function &setInputVariablesGroups(&$value)
+    public function setInputVariablesGroups(&$value)
     {
         $this->_inputVariablesGroups = $value;
     }

PHPSkills/FactorGraphs/VariableFactory.php

@@ -11,7 +11,7 @@ class VariableFactory
 
     public function __construct($variablePriorInitializer)
     {
-        $this->_variablePriorInitializer = $variablePriorInitializer;
+        $this->_variablePriorInitializer = &$variablePriorInitializer;
     }
 
     public function createBasicVariable()
@@ -22,7 +22,8 @@ class VariableFactory
 
     public function createKeyedVariable($key)
     {
-        $newVar = new KeyedVariable($key, $this->_variablePriorInitializer());
+        $initializer = $this->_variablePriorInitializer;
+        $newVar = new KeyedVariable($key, "key variable", $initializer());
         return $newVar;
     }
 }

PHPSkills/HashMap.php

@@ -1,5 +1,7 @@
 <?php
 
+namespace Moserware\Skills;
+
 class HashMap
 {
     private $_hashToValue = array();

PHPSkills/Numerics/GaussianDistribution.php

@@ -81,9 +81,19 @@ class GaussianDistribution
         $result = new GaussianDistribution();
         $result->_precision = $precision;
         $result->_precisionMean = $precisionMean;
-        $result->_variance = 1.0/$precision;
+
-        $result->_standardDeviation = sqrt($result->_variance);
+        if($precision != 0)
-        $result->_mean = $result->_precisionMean/$result->_precision;
+        {
+            $result->_variance = 1.0/$precision;
+            $result->_standardDeviation = sqrt($result->_variance);
+            $result->_mean = $result->_precisionMean/$result->_precision;
+        }
+        else
+        {
+            $result->_variance = \INF;
+            $result->_standardDeviation = \INF;
+            $result->_mean = \NAN;
+        }
         return $result;
     }
     

PHPSkills/RatingContainer.php

@@ -9,7 +9,7 @@ class RatingContainer
 
     public function __construct()
     {
-        $this->_playerToRating = new \HashMap();
+        $this->_playerToRating = new HashMap();
     }
 
     public function getRating($player)

PHPSkills/TrueSkill/Factors/GaussianFactor.php

@@ -31,7 +31,7 @@ abstract class GaussianFactor extends Factor
 
     public function createVariableToMessageBinding(Variable &$variable)
     {
-        return parent::createVariableToMessageBinding($variable,
+        return parent::createVariableToMessageBindingWithMessage($variable,
                                                       new Message(
                                                           GaussianDistribution::fromPrecisionMean(0, 0),
                                                           "message from {0} to {1}", $this));

PHPSkills/TrueSkill/Factors/GaussianPriorFactor.php

@@ -23,11 +23,11 @@ class GaussianPriorFactor extends GaussianFactor
     {
         parent::__construct("Prior value going to {0}");
         $this->_newMessage = new GaussianDistribution($mean, sqrt($variance));
-        $this->createVariableToMessageBinding($variable,
+        $newMessage = new Message(GaussianDistribution::fromPrecisionMean(0, 0),
-                                               new Message(
-                                                   GaussianDistribution::fromPrecisionMean(0, 0),
                                                        "message from {0} to {1}",
-                                                   $this, variable));
+                                                   $this, $variable);
+
+        $this->createVariableToMessageBindingWithMessage($variable, $newMessage);
     }
 
     protected function updateMessageVariable(Message &$message, Variable &$variable)

PHPSkills/TrueSkill/Layers/PlayerPriorValuesToSkillsLayer.php

@@ -35,11 +35,12 @@ class PlayerPriorValuesToSkillsLayer extends TrueSkillFactorGraphLayer
             {
                 $currentTeamPlayerRating = $currentTeam->getRating($currentTeamPlayer);
                 $playerSkill = $this->createSkillOutputVariable($currentTeamPlayer);
-                $this->addLayerFactor($this->createPriorFactor($currentTeamPlayer, $currentTeamPlayerRating, $playerSkill));
+                $priorFactor = $this->createPriorFactor($currentTeamPlayer, $currentTeamPlayerRating, $playerSkill);
+                $this->addLayerFactor($priorFactor);
                 $currentTeamSkills[] = $playerSkill;
             }
 
-            $outputVariablesGroups = $this->getOutputVariablesGroups();
+            $outputVariablesGroups = &$this->getOutputVariablesGroups();
             $outputVariablesGroups[] = $currentTeamSkills;
         }
     }

PHPSkills/TrueSkill/Layers/PlayerSkillsToPerformancesLayer.php

@@ -52,7 +52,7 @@ class PlayerSkillsToPerformancesLayer extends TrueSkillFactorGraphLayer
                 array_map(
                         function($likelihood)
                         {
-                            return $this->scheduleStep("Skill to Perf step", $likelihood, 0);
+                            return new ScheduleStep("Skill to Perf step", $likelihood, 0);
                         },
                         $this->getLocalFactors()),
                 "All skill to performance sending");

PHPSkills/TrueSkill/TrueSkillFactorGraph.php

@@ -15,6 +15,7 @@ require_once(dirname(__FILE__) . '/Layers/PlayerSkillsToPerformancesLayer.php');
 require_once(dirname(__FILE__) . '/Layers/TeamDifferencesComparisonLayer.php');
 require_once(dirname(__FILE__) . '/Layers/TeamPerformancesToTeamPerformanceDifferencesLayer.php');
 
+use Moserware\Numerics\GaussianDistribution;
 use Moserware\Skills\GameInfo;
 use Moserware\Skills\Rating;
 use Moserware\Skills\FactorGraphs\FactorGraph;
@@ -32,8 +33,7 @@ class TrueSkillFactorGraph extends FactorGraph
 {
     private $_gameInfo;
     private $_layers;
-    private $_priorLayer;
+    private $_priorLayer;    
-    private $_variableFactory;
 
     public function __construct(GameInfo &$gameInfo, &$teams, array $teamRanks)
     {
@@ -44,8 +44,8 @@ class TrueSkillFactorGraph extends FactorGraph
                                         {
                                             return GaussianDistribution::fromPrecisionMean(0, 0);
                                         });
+                                        
         $this->setVariableFactory($newFactory);
-
         $this->_layers = array(
                               $this->_priorLayer,
                               new PlayerSkillsToPerformancesLayer($this),