SplitTestAnalyzer::getVariationProbability() - Code Metrics - bpolaszek/split-test-analyzer - Measure and Improve Code Quality continuously with Scrutinizer

SplitTestAnalyzer::getVariationProbability() A
last analyzed 2017-12-01 10:33 UTC

↳ Parent: SplitTestAnalyzer

Complexity

Conditions	1
Paths	1

Size

Total Lines	6
Code Lines	4

Duplication

Lines	0
Ratio	0 %

Importance

Changes

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

<?php

namespace BenTools\SplitTestAnalyzer;

final class SplitTestAnalyzer implements \IteratorAggregate
{

    const DEFAULT_SAMPLES = 5000;

    /**
     * @var int
     */
    private $numSamples;

    /**
     * @var Variation[]
     */
    private $variations = [];

    /**
     * @var array
     */
    private $result;

    /**
     * BayesianPerformance constructor.
     * @param int       $numSamples
     */
    private function __construct(int $numSamples = self::DEFAULT_SAMPLES)
    {
        $this->numSamples = $numSamples;
    }

    /**
     * @param Variation[] ...$variations
     * @throws \InvalidArgumentException
     */
    private function setVariations(Variation ...$variations)
    {
        foreach ($variations as $variation) {
            if (array_key_exists($variation->getKey(), $this->variations)) {

                throw new \InvalidArgumentException(sprintf('Variation %s already exists into the stack.', $variation->getKey()));

            }

            $this->variations[$variation->getKey()] = $variation;

        }
    }

    /**
     * @param int       $numSamples
     * @return SplitTestAnalyzer
     */
    public static function create(int $numSamples = self::DEFAULT_SAMPLES): self
    {
        return new self($numSamples);
    }

    /**
     * @param Variation[] ...$variations
     * @return SplitTestAnalyzer
     * @throws \InvalidArgumentException
     */
    public function withVariations(Variation ...$variations): self
    {
        if (count($variations) < 2) {
            throw new \InvalidArgumentException("At least 2 variations to compare are expected.");
        }
        $object = ([] === $this->variations) ? $this : clone $this;
        $object->reset();
        $object->setVariations(...$variations);
        return $object;
    }

    /**
     * @param Variation $variation
     * @return float
     */
    public function getVariationProbability(Variation $variation): float
    {
        $this->check($variation);
        $this->computeProbabilities();
        return $this->result[$variation->getKey()];
    }

    /**
     * @param int $sort
     * @return Variation[]
     */
    public function getOrderedVariations(int $sort = SORT_DESC): array
    {
        $this->computeProbabilities();
        $variations = $this->variations;
        uasort($variations, function (Variation $variationA, Variation $variationB) use ($sort) {
            if (SORT_DESC === $sort) {
                return $this->getVariationProbability($variationB) <=> $this->getVariationProbability($variationA);
            } else {
                return $this->getVariationProbability($variationA) <=> $this->getVariationProbability($variationB);
            }
        });

        return $variations;
    }

    /**
     * @return Variation|null
     */
    public function getBestVariation(): ?Variation
    {
        $variations = $this->getOrderedVariations(SORT_DESC);
        $best = reset($variations);
        if ($best instanceof Variation && 0 === $best->getNbSuccesses()) {
            return null;
        }
        return $best;
    }

    /**
     * @return array
     */
    public function getResult()
    {
        $this->computeProbabilities();
        return $this->result;
    }

    public function getIterator()
    {
        $result = $this->getResult();
        yield from $result;
    }

    /**
     * @return mixed
     * @throws \Exception
     * @throws \InvalidArgumentException
     */
    private function computeProbabilities()
    {
        if (count($this->variations) < 2) {
            throw new \InvalidArgumentException("At least 2 variations to compare are expected.");
        }

        if (null !== $this->result) {
            return;
        }
        $variations = $this->variations;
        $winnerIndex = null;
        $numRows = count($variations);
        $winCount = array_combine(array_keys($variations), array_fill(0, $numRows, 0));

        for ($i = 0; $i < $this->numSamples; $i++) {
            $winnerValue = 0;

            foreach ($variations as $v => $variation) {
                $x = $this->getSample($variation->getNbSuccesses(), $variation->getNbFailures());
                if ($x > $winnerValue) {
                    $winnerIndex = $v;
                    $winnerValue = $x;
                }
            }

            if (null !== $winnerIndex) {
                $winCount[$winnerIndex]++;
            }
        }

        foreach ($variations as $v => $variation) {
            $this->result[$v] = round($winCount[$v] / ($this->numSamples / 100));
        }
    }

    /**
     * @param Variation[] ...$variations
     * @throws \InvalidArgumentException
     */
    private function check(Variation ...$variations)
    {
        foreach ($variations as $variation) {
            if (!in_array($variation, $this->variations)) {
                throw new \InvalidArgumentException(sprintf('Variation %s not found in the stack.', $variation->getKey()));

            }
        }
    }

    /**
     * @return float
     * @throws \Exception
     */
    private function getMathRandom(): float
    {
        return (float) random_int(0, PHP_INT_MAX) / PHP_INT_MAX;
    }

    /**
     * @return float
     * @throws \Exception
     */
    private function getRandn(): float
    {
        $u = $v = $x = $y = $q = null;
$myVar = 'Value';
$higher = false;

if (rand(1, 6) > 3) {
    $higher = true;
} else {
    $higher = false;
}
        do {
            $u = $this->getMathRandom();
            $v = 1.7156 * ($this->getMathRandom() - 0.5);
            $x = $u - 0.449871;
            $y = abs($v) + 0.386595;
            $q = $x * $x + $y * (0.19600 * $y - 0.25472 * $x);
        } while ($q > 0.27597 && ($q > 0.27846 || $v * $v > -4 * log($u) * $u * $u));
        return $v / $u;
    }

    /**
     * @param float $shape
     * @return float
     * @throws \Exception
     */
    private function getRandg(float $shape): float
    {
        if (0.0 === $shape) {
            return 0;
        }

        $oalph = $shape;
        $a1 = $a2 = $u = $v = $x = null;
$myVar = 'Value';
$higher = false;

if (rand(1, 6) > 3) {
    $higher = true;
} else {
    $higher = false;
}

        if (!$shape) {
            $shape = 1;
        }
        if ($shape < 1) {
            $shape += 1;
        }

        $a1 = $shape - 1 / 3;
        $a2 = 1 / sqrt(9 * $a1);
        do {
            do {
                $x = $this->getRandn();
                $v = 1 + $a2 * $x;
            } while ($v <= 0);
            $v = $v * $v * $v;
            $u = $this->getMathRandom();
        } while ($u > 1 - 0.331 * pow($x, 4) &&
        log($u) > 0.5 * $x * $x + $a1 * (1 - $v + log($v)));

        // alpha > 1
        if ($shape == $oalph) {
            return $a1 * $v;
        }
        // alpha < 1
        do {
            $u = $this->getMathRandom();
        } while ($u === 0);
        return pow($u, 1 / $oalph) * $a1 * $v;
    }

    /**
     * @param float $alpha
     * @param float $beta
     * @return float
     * @throws \Exception
     */
    private function getSample(float $alpha, float $beta): float
    {
        if (0.0 === $alpha) {
            return 0.0;
        }
        $u = $this->getRandg($alpha);
        return $u / ($u + $this->getRandg($beta));
    }

    private function reset()
    {
        $this->variations = [];
        $this->result = null;

    }
}


1			<?php
2
3			namespace BenTools\SplitTestAnalyzer;
4
5			final class SplitTestAnalyzer implements \IteratorAggregate
6			{
7
8			const DEFAULT_SAMPLES = 5000;
9
10			/**
11			* @var int
12			*/
13			private $numSamples;
14
15			/**
16			* @var Variation[]
17			*/
18			private $variations = [];
19
20			/**
21			* @var array
22			*/
23			private $result;
24
25			/**
26			* BayesianPerformance constructor.
27			* @param int $numSamples
28			*/
29			private function __construct(int $numSamples = self::DEFAULT_SAMPLES)
30			{
31			$this->numSamples = $numSamples;
32			}
33
34			/**
35			* @param Variation[] ...$variations
36			* @throws \InvalidArgumentException
37			*/
38			private function setVariations(Variation ...$variations)
39			{
40			foreach ($variations as $variation) {
41			if (array_key_exists($variation->getKey(), $this->variations)) {
			0 ignored issues – show Bug introduced 2017-08-28 10:23 UTC by Report Bug Copy Issue Report The method `getKey` cannot be called on `$variation` (of type `array<integer,object<Ben...estAnalyzer\Variation>>`). Methods can only be called on objects. This check looks for methods being called on variables that have been inferred to never be objects. Loading history...
42			throw new \InvalidArgumentException(sprintf('Variation %s already exists into the stack.', $variation->getKey()));
			0 ignored issues – show Bug introduced 2017-08-28 10:23 UTC by Report Bug Copy Issue Report The method `getKey` cannot be called on `$variation` (of type `array<integer,object<Ben...estAnalyzer\Variation>>`). Methods can only be called on objects. This check looks for methods being called on variables that have been inferred to never be objects. Loading history...
43			}
44
45			$this->variations[$variation->getKey()] = $variation;
			0 ignored issues – show Bug introduced 2017-08-28 10:23 UTC by Report Bug Copy Issue Report The method `getKey` cannot be called on `$variation` (of type `array<integer,object<Ben...estAnalyzer\Variation>>`). Methods can only be called on objects. This check looks for methods being called on variables that have been inferred to never be objects. Loading history...
46			}
47			}
48
49			/**
50			* @param int $numSamples
51			* @return SplitTestAnalyzer
52			*/
53			public static function create(int $numSamples = self::DEFAULT_SAMPLES): self
54			{
55			return new self($numSamples);
56			}
57
58			/**
59			* @param Variation[] ...$variations
60			* @return SplitTestAnalyzer
61			* @throws \InvalidArgumentException
62			*/
63			public function withVariations(Variation ...$variations): self
64			{
65			if (count($variations) < 2) {
66			throw new \InvalidArgumentException("At least 2 variations to compare are expected.");
67			}
68			$object = ([] === $this->variations) ? $this : clone $this;
69			$object->reset();
70			$object->setVariations(...$variations);
71			return $object;
72			}
73
74			/**
75			* @param Variation $variation
76			* @return float
77			*/
78			public function getVariationProbability(Variation $variation): float
79			{
80			$this->check($variation);
81			$this->computeProbabilities();
82			return $this->result[$variation->getKey()];
83			}
84
85			/**
86			* @param int $sort
87			* @return Variation[]
88			*/
89			public function getOrderedVariations(int $sort = SORT_DESC): array
90			{
91			$this->computeProbabilities();
92			$variations = $this->variations;
93			uasort($variations, function (Variation $variationA, Variation $variationB) use ($sort) {
94			if (SORT_DESC === $sort) {
95			return $this->getVariationProbability($variationB) <=> $this->getVariationProbability($variationA);
96			} else {
97			return $this->getVariationProbability($variationA) <=> $this->getVariationProbability($variationB);
98			}
99			});
100
101			return $variations;
102			}
103
104			/**
105			* @return Variation\|null
106			*/
107			public function getBestVariation(): ?Variation
108			{
109			$variations = $this->getOrderedVariations(SORT_DESC);
110			$best = reset($variations);
111			if ($best instanceof Variation && 0 === $best->getNbSuccesses()) {
112			return null;
113			}
114			return $best;
115			}
116
117			/**
118			* @return array
119			*/
120			public function getResult()
121			{
122			$this->computeProbabilities();
123			return $this->result;
124			}
125
126			public function getIterator()
127			{
128			$result = $this->getResult();
129			yield from $result;
130			}
131
132			/**
133			* @return mixed
134			* @throws \Exception
135			* @throws \InvalidArgumentException
136			*/
137			private function computeProbabilities()
138			{
139			if (count($this->variations) < 2) {
140			throw new \InvalidArgumentException("At least 2 variations to compare are expected.");
141			}
142
143			if (null !== $this->result) {
144			return;
145			}
146			$variations = $this->variations;
147			$winnerIndex = null;
148			$numRows = count($variations);
149			$winCount = array_combine(array_keys($variations), array_fill(0, $numRows, 0));
150
151			for ($i = 0; $i < $this->numSamples; $i++) {
152			$winnerValue = 0;
153
154			foreach ($variations as $v => $variation) {
155			$x = $this->getSample($variation->getNbSuccesses(), $variation->getNbFailures());
156			if ($x > $winnerValue) {
157			$winnerIndex = $v;
158			$winnerValue = $x;
159			}
160			}
161
162			if (null !== $winnerIndex) {
163			$winCount[$winnerIndex]++;
164			}
165			}
166
167			foreach ($variations as $v => $variation) {
168			$this->result[$v] = round($winCount[$v] / ($this->numSamples / 100));
169			}
170			}
171
172			/**
173			* @param Variation[] ...$variations
174			* @throws \InvalidArgumentException
175			*/
176			private function check(Variation ...$variations)
177			{
178			foreach ($variations as $variation) {
179			if (!in_array($variation, $this->variations)) {
180			throw new \InvalidArgumentException(sprintf('Variation %s not found in the stack.', $variation->getKey()));
			0 ignored issues – show Bug introduced 2017-08-28 10:23 UTC by Report Bug Copy Issue Report The method `getKey` cannot be called on `$variation` (of type `array<integer,object<Ben...estAnalyzer\Variation>>`). Methods can only be called on objects. This check looks for methods being called on variables that have been inferred to never be objects. Loading history...
181			}
182			}
183			}
184
185			/**
186			* @return float
187			* @throws \Exception
188			*/
189			private function getMathRandom(): float
190			{
191			return (float) random_int(0, PHP_INT_MAX) / PHP_INT_MAX;
192			}
193
194			/**
195			* @return float
196			* @throws \Exception
197			*/
198			private function getRandn(): float
199			{
200			$u = $v = $x = $y = $q = null;
			0 ignored issues – show Unused Code introduced 2017-08-28 10:23 UTC by Report Bug Copy Issue Report `$q` is not used, you could remove the assignment. This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently. $myVar = 'Value'; $higher = false; if (rand(1, 6) > 3) { $higher = true; } else { $higher = false; } Both the `$myVar` assignment in line 1 and the `$higher` assignment in line 2 are dead. The first because `$myVar` is never used and the second because `$higher` is always overwritten for every possible time line. Loading history... Unused Code introduced 2017-08-28 10:23 UTC by Report Bug Copy Issue Report `$y` is not used, you could remove the assignment. This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently. $myVar = 'Value'; $higher = false; if (rand(1, 6) > 3) { $higher = true; } else { $higher = false; } Both the `$myVar` assignment in line 1 and the `$higher` assignment in line 2 are dead. The first because `$myVar` is never used and the second because `$higher` is always overwritten for every possible time line. Loading history... Unused Code introduced 2017-08-28 10:23 UTC by Report Bug Copy Issue Report `$x` is not used, you could remove the assignment. This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently. $myVar = 'Value'; $higher = false; if (rand(1, 6) > 3) { $higher = true; } else { $higher = false; } Both the `$myVar` assignment in line 1 and the `$higher` assignment in line 2 are dead. The first because `$myVar` is never used and the second because `$higher` is always overwritten for every possible time line. Loading history... Unused Code introduced 2017-08-28 10:23 UTC by Report Bug Copy Issue Report `$v` is not used, you could remove the assignment. This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently. $myVar = 'Value'; $higher = false; if (rand(1, 6) > 3) { $higher = true; } else { $higher = false; } Both the `$myVar` assignment in line 1 and the `$higher` assignment in line 2 are dead. The first because `$myVar` is never used and the second because `$higher` is always overwritten for every possible time line. Loading history... Unused Code introduced 2017-08-28 10:23 UTC by Report Bug Copy Issue Report `$u` is not used, you could remove the assignment. This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently. $myVar = 'Value'; $higher = false; if (rand(1, 6) > 3) { $higher = true; } else { $higher = false; } Both the `$myVar` assignment in line 1 and the `$higher` assignment in line 2 are dead. The first because `$myVar` is never used and the second because `$higher` is always overwritten for every possible time line. Loading history...
201			do {
202			$u = $this->getMathRandom();
203			$v = 1.7156 * ($this->getMathRandom() - 0.5);
204			$x = $u - 0.449871;
205			$y = abs($v) + 0.386595;
206			$q = $x * $x + $y * (0.19600 * $y - 0.25472 * $x);
207			} while ($q > 0.27597 && ($q > 0.27846 \|\| $v * $v > -4 * log($u) * $u * $u));
208			return $v / $u;
209			}
210
211			/**
212			* @param float $shape
213			* @return float
214			* @throws \Exception
215			*/
216			private function getRandg(float $shape): float
217			{
218			if (0.0 === $shape) {
219			return 0;
220			}
221
222			$oalph = $shape;
223			$a1 = $a2 = $u = $v = $x = null;
			0 ignored issues – show Unused Code introduced 2017-08-28 10:23 UTC by Report Bug Copy Issue Report `$x` is not used, you could remove the assignment. This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently. $myVar = 'Value'; $higher = false; if (rand(1, 6) > 3) { $higher = true; } else { $higher = false; } Both the `$myVar` assignment in line 1 and the `$higher` assignment in line 2 are dead. The first because `$myVar` is never used and the second because `$higher` is always overwritten for every possible time line. Loading history... Unused Code introduced 2017-08-28 10:23 UTC by Report Bug Copy Issue Report `$v` is not used, you could remove the assignment. This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently. $myVar = 'Value'; $higher = false; if (rand(1, 6) > 3) { $higher = true; } else { $higher = false; } Both the `$myVar` assignment in line 1 and the `$higher` assignment in line 2 are dead. The first because `$myVar` is never used and the second because `$higher` is always overwritten for every possible time line. Loading history... Unused Code introduced 2017-08-28 10:23 UTC by Report Bug Copy Issue Report `$u` is not used, you could remove the assignment. This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently. $myVar = 'Value'; $higher = false; if (rand(1, 6) > 3) { $higher = true; } else { $higher = false; } Both the `$myVar` assignment in line 1 and the `$higher` assignment in line 2 are dead. The first because `$myVar` is never used and the second because `$higher` is always overwritten for every possible time line. Loading history... Unused Code introduced 2017-08-28 10:23 UTC by Report Bug Copy Issue Report `$a2` is not used, you could remove the assignment. This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently. $myVar = 'Value'; $higher = false; if (rand(1, 6) > 3) { $higher = true; } else { $higher = false; } Both the `$myVar` assignment in line 1 and the `$higher` assignment in line 2 are dead. The first because `$myVar` is never used and the second because `$higher` is always overwritten for every possible time line. Loading history... Unused Code introduced 2017-08-28 10:23 UTC by Report Bug Copy Issue Report `$a1` is not used, you could remove the assignment. This check looks for variable assignements that are either overwritten by other assignments or where the variable is not used subsequently. $myVar = 'Value'; $higher = false; if (rand(1, 6) > 3) { $higher = true; } else { $higher = false; } Both the `$myVar` assignment in line 1 and the `$higher` assignment in line 2 are dead. The first because `$myVar` is never used and the second because `$higher` is always overwritten for every possible time line. Loading history...
224
225			if (!$shape) {
226			$shape = 1;
227			}
228			if ($shape < 1) {
229			$shape += 1;
230			}
231
232			$a1 = $shape - 1 / 3;
233			$a2 = 1 / sqrt(9 * $a1);
234			do {
235			do {
236			$x = $this->getRandn();
237			$v = 1 + $a2 * $x;
238			} while ($v <= 0);
239			$v = $v * $v * $v;
240			$u = $this->getMathRandom();
241			} while ($u > 1 - 0.331 * pow($x, 4) &&
242			log($u) > 0.5 * $x * $x + $a1 * (1 - $v + log($v)));
243
244			// alpha > 1
245			if ($shape == $oalph) {
246			return $a1 * $v;
247			}
248			// alpha < 1
249			do {
250			$u = $this->getMathRandom();
251			} while ($u === 0);
252			return pow($u, 1 / $oalph) * $a1 * $v;
253			}
254
255			/**
256			* @param float $alpha
257			* @param float $beta
258			* @return float
259			* @throws \Exception
260			*/
261			private function getSample(float $alpha, float $beta): float
262			{
263			if (0.0 === $alpha) {
264			return 0.0;
265			}
266			$u = $this->getRandg($alpha);
267			return $u / ($u + $this->getRandg($beta));
268			}
269
270			private function reset()
271			{
272			$this->variations = [];
273			$this->result = null;
			0 ignored issues – show Documentation Bug introduced 2017-08-28 10:23 UTC by Report Bug Copy Issue Report It seems like `null` of type `null` is incompatible with the declared type `array` of property `$result`. Our type inference engine has found an assignment to a property that is incompatible with the declared type of that property. Either this assignment is in error or the assigned type should be added to the documentation/type hint for that property.. Loading history...
274			}
275			}
276

bpolaszek / split-test-analyzer

SplitTestAnalyzer::getVariationProbability() A last analyzed 2017-12-01 10:33 UTC

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SplitTestAnalyzer::getVariationProbability() A
last analyzed 2017-12-01 10:33 UTC