EloSystem::__construct() - Code Metrics - alcalyn/elo - Measure and Improve Code Quality continuously with Scrutinizer

EloSystem::__construct() A
last analyzed 2016-06-13 19:45 UTC

↳ Parent: EloSystem

Complexity

Conditions	1
Paths	1

Size

Total Lines	6
Code Lines	4

Duplication

Lines	0
Ratio	0 %

Importance

Changes	1
Bugs	0	Features	0

Metric	Value
c	1
b	0
f	0
dl	0
loc	6
rs	9.4285
cc	1
eloc	4
nc	1
nop	3

<?php

namespace Alcalyn\Elo;

use Alcalyn\Elo\Exception\EloCoefficientException;

class EloSystem
{
    /**
     * F Factor. Determines how quickly elo scores change.
     * Default is 16
     * 
     * @var integer
     */
    private $kFactor;
    
    /**
     * Defines the range of elo.
     * Default is 400
     * 
     * @var integer 
     */
    private $interval;
    
    /**
     * Defines approximatively the power between intervals.
     * Default is 10
     * 
     * @var integer
     */
    private $pow;
    
    /**
     * Constructor
     * 
     * @param integer $kFactor
     * @param integer $interval
     * @param integer $pow
     */
    public function __construct($kFactor = 16, $interval = 400, $pow = 10)
    {
        $this->kFactor = $kFactor;
        $this->interval = $interval;
        $this->pow = $pow;
    }
    
    /**
     * Calculate new elo scores
     * 
     * @param double $elo0 elo score of player 0
     * @param double $elo1 elo score of player 1
     * @param double $win win coef for player 0. Set 1 to say that player 0 won
     * @param double $reliability0 elo reliability for player 0
     * @param double $reliability1 elo reliability for player 1
     * @param integer $kFactor0 override k factor for player 0
     * @param integer $kFactor1 override k factor for player 1
     * 
     * @return double[] with new elo score at indexes 0 and 1 for player 0 and 1
     */
    public function calculate($elo0, $elo1, $win, $reliability0 = 1.0, $reliability1 = 1.0, $kFactor0 = null, $kFactor1 = null)
    {
        self::checkCoef($reliability0, 'reliability0');
        self::checkCoef($reliability1, 'reliability1');
        self::checkCoef($win, 'win');
        
        $kFactor0 = (null === $kFactor0) ? $this->kFactor : $kFactor0;
        $kFactor1 = (null === $kFactor1) ? $this->kFactor : $kFactor1;
        
        /**
         * Calculate probability 0 have to beat 1
         */
        $proba = $this->proba($elo0, $elo1);
        
        /**
         * Calculate elo changement
         */
        $eloUpdate0 = $win - $proba;
        $eloUpdate1 = -$eloUpdate0;
        
        /**
         * Calculate local reliability to avoid 0 and 0 reliability for new players
         * (if two new players have 0 and 0.1 reliability, they are rectified to 0.9 and 1)
         */
        self::rectifyReliabilityCoefs($reliability0, $reliability1);
        
        /**
         * Apply coefs K-factor and reliability of each other
         */
        $eloUpdate0 *= $kFactor0 * $reliability1 ;
        $eloUpdate1 *= $kFactor1 * $reliability0 ;
        
        return array($elo0 + $eloUpdate0, $elo1 + $eloUpdate1);
    }
    
    /**
     * Player 0 beat player 1
     * 
     * @param double $elo0 elo score of player 0
     * @param double $elo1 elo score of player 1
     * @param double $reliability0 elo reliability for player 0
     * @param double $reliability1 elo reliability for player 1
     * 
     * @return double[] with new elo score at indexes 0 and 1 for player 0 and 1
     */
    public function win($elo0, $elo1, $reliability0 = 1.0, $reliability1 = 1.0, $kFactor0 = null, $kFactor1 = null)
    {
        return $this->calculate($elo0, $elo1, 1, $reliability0, $reliability1, $kFactor0, $kFactor1);
    }
    
    /**
     * Player 0 lose against player 1
     * 
     * @param double $elo0 elo score of player 0
     * @param double $elo1 elo score of player 1
     * @param double $reliability0 elo reliability for player 0
     * @param double $reliability1 elo reliability for player 1
     * 
     * @return double[] with new elo score at indexes 0 and 1 for player 0 and 1
     */
    public function lose($elo0, $elo1, $reliability0 = 1.0, $reliability1 = 1.0, $kFactor0 = null, $kFactor1 = null)
    {
        return $this->calculate($elo0, $elo1, 0, $reliability0, $reliability1, $kFactor0, $kFactor1);
    }
    
    /**
     * Player 0 and player 1 have made a draw game
     * 
     * @param double $elo0 elo score of player 0
     * @param double $elo1 elo score of player 1
     * @param double $reliability0 elo reliability for player 0
     * @param double $reliability1 elo reliability for player 1
     * 
     * @return double[] with new elo score at indexes 0 and 1 for player 0 and 1
     */
    public function draw($elo0, $elo1, $reliability0 = 1.0, $reliability1 = 1.0, $kFactor0 = null, $kFactor1 = null)
    {
        return $this->calculate($elo0, $elo1, 0.5, $reliability0, $reliability1, $kFactor0, $kFactor1);
    }
    
    /**
     * Return probability rate that $elo0 beat $elo1
     * 
     * @param double $elo0
     * @param double $elo1
     * 
     * @return double
     */
    public function proba($elo0, $elo1)
    {
        return 1 / (1 + pow($this->pow, ($elo1 - $elo0) / $this->interval)) ;
    }
    
    /**
     * Increase coefficients the same value so one of them reaches 1
     * 
     * @param double $coef0
     * @param double $coef1
     */
    private static function rectifyReliabilityCoefs(&$coef0, &$coef1)
    {
        $reliabilityRectification = 1 - max($coef0, $coef1);
        
        $coef0 += $reliabilityRectification;
        $coef1 += $reliabilityRectification;
    }
    
    /**
     * Check if $coef is in range [0;1]
     * 
     * @param double $coef
     * @param string $variableName
     */
    private static function checkCoef($coef, $variableName)
    {
        if (($coef < 0) || ($coef > 1)) {
            throw new EloCoefficientException($coef, $variableName);
        }
    }
}


1			<?php
2
3			namespace Alcalyn\Elo;
4
5			use Alcalyn\Elo\Exception\EloCoefficientException;
6
7			class EloSystem
8			{
9			/**
10			* F Factor. Determines how quickly elo scores change.
11			* Default is 16
12			*
13			* @var integer
14			*/
15			private $kFactor;
16
17			/**
18			* Defines the range of elo.
19			* Default is 400
20			*
21			* @var integer
22			*/
23			private $interval;
24
25			/**
26			* Defines approximatively the power between intervals.
27			* Default is 10
28			*
29			* @var integer
30			*/
31			private $pow;
32
33			/**
34			* Constructor
35			*
36			* @param integer $kFactor
37			* @param integer $interval
38			* @param integer $pow
39			*/
40			public function __construct($kFactor = 16, $interval = 400, $pow = 10)
41			{
42			$this->kFactor = $kFactor;
43			$this->interval = $interval;
44			$this->pow = $pow;
45			}
46
47			/**
48			* Calculate new elo scores
49			*
50			* @param double $elo0 elo score of player 0
51			* @param double $elo1 elo score of player 1
52			* @param double $win win coef for player 0. Set 1 to say that player 0 won
53			* @param double $reliability0 elo reliability for player 0
54			* @param double $reliability1 elo reliability for player 1
55			* @param integer $kFactor0 override k factor for player 0
56			* @param integer $kFactor1 override k factor for player 1
57			*
58			* @return double[] with new elo score at indexes 0 and 1 for player 0 and 1
59			*/
60			public function calculate($elo0, $elo1, $win, $reliability0 = 1.0, $reliability1 = 1.0, $kFactor0 = null, $kFactor1 = null)
61			{
62			self::checkCoef($reliability0, 'reliability0');
63			self::checkCoef($reliability1, 'reliability1');
64			self::checkCoef($win, 'win');
65
66			$kFactor0 = (null === $kFactor0) ? $this->kFactor : $kFactor0;
67			$kFactor1 = (null === $kFactor1) ? $this->kFactor : $kFactor1;
68
69			/**
70			* Calculate probability 0 have to beat 1
71			*/
72			$proba = $this->proba($elo0, $elo1);
73
74			/**
75			* Calculate elo changement
76			*/
77			$eloUpdate0 = $win - $proba;
78			$eloUpdate1 = -$eloUpdate0;
79
80			/**
81			* Calculate local reliability to avoid 0 and 0 reliability for new players
82			* (if two new players have 0 and 0.1 reliability, they are rectified to 0.9 and 1)
83			*/
84			self::rectifyReliabilityCoefs($reliability0, $reliability1);
85
86			/**
87			* Apply coefs K-factor and reliability of each other
88			*/
89			$eloUpdate0 = $kFactor0 $reliability1 ;
90			$eloUpdate1 = $kFactor1 $reliability0 ;
91
92			return array($elo0 + $eloUpdate0, $elo1 + $eloUpdate1);
93			}
94
95			/**
96			* Player 0 beat player 1
97			*
98			* @param double $elo0 elo score of player 0
99			* @param double $elo1 elo score of player 1
100			* @param double $reliability0 elo reliability for player 0
101			* @param double $reliability1 elo reliability for player 1
102			*
103			* @return double[] with new elo score at indexes 0 and 1 for player 0 and 1
104			*/
105			public function win($elo0, $elo1, $reliability0 = 1.0, $reliability1 = 1.0, $kFactor0 = null, $kFactor1 = null)
106			{
107			return $this->calculate($elo0, $elo1, 1, $reliability0, $reliability1, $kFactor0, $kFactor1);
108			}
109
110			/**
111			* Player 0 lose against player 1
112			*
113			* @param double $elo0 elo score of player 0
114			* @param double $elo1 elo score of player 1
115			* @param double $reliability0 elo reliability for player 0
116			* @param double $reliability1 elo reliability for player 1
117			*
118			* @return double[] with new elo score at indexes 0 and 1 for player 0 and 1
119			*/
120			public function lose($elo0, $elo1, $reliability0 = 1.0, $reliability1 = 1.0, $kFactor0 = null, $kFactor1 = null)
121			{
122			return $this->calculate($elo0, $elo1, 0, $reliability0, $reliability1, $kFactor0, $kFactor1);
123			}
124
125			/**
126			* Player 0 and player 1 have made a draw game
127			*
128			* @param double $elo0 elo score of player 0
129			* @param double $elo1 elo score of player 1
130			* @param double $reliability0 elo reliability for player 0
131			* @param double $reliability1 elo reliability for player 1
132			*
133			* @return double[] with new elo score at indexes 0 and 1 for player 0 and 1
134			*/
135			public function draw($elo0, $elo1, $reliability0 = 1.0, $reliability1 = 1.0, $kFactor0 = null, $kFactor1 = null)
136			{
137			return $this->calculate($elo0, $elo1, 0.5, $reliability0, $reliability1, $kFactor0, $kFactor1);
138			}
139
140			/**
141			* Return probability rate that $elo0 beat $elo1
142			*
143			* @param double $elo0
144			* @param double $elo1
145			*
146			* @return double
147			*/
148			public function proba($elo0, $elo1)
149			{
150			return 1 / (1 + pow($this->pow, ($elo1 - $elo0) / $this->interval)) ;
151			}
152
153			/**
154			* Increase coefficients the same value so one of them reaches 1
155			*
156			* @param double $coef0
157			* @param double $coef1
158			*/
159			private static function rectifyReliabilityCoefs(&$coef0, &$coef1)
160			{
161			$reliabilityRectification = 1 - max($coef0, $coef1);
162
163			$coef0 += $reliabilityRectification;
164			$coef1 += $reliabilityRectification;
165			}
166
167			/**
168			* Check if $coef is in range [0;1]
169			*
170			* @param double $coef
171			* @param string $variableName
172			*/
173			private static function checkCoef($coef, $variableName)
174			{
175			if (($coef < 0) \|\| ($coef > 1)) {
176			throw new EloCoefficientException($coef, $variableName);
177			}
178			}
179			}
180

alcalyn / elo

EloSystem::__construct() A last analyzed 2016-06-13 19:45 UTC

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EloSystem::__construct() A
last analyzed 2016-06-13 19:45 UTC