Normal::xFromZScore() - Code Metrics - Inspection of "Added Exponential Distribution and refined Poisson..." - JordanRL/Fermat - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — dev ( 021c9f...a2bcd2 )

by Jordan

created 2017-01-11 07:38 UTC

Normal::xFromZScore() A

↳ Parent: Normal

Complexity

Conditions	1
Paths	1

Size

Total Lines	6
Code Lines	3

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	3
nc	1
nop	1

<?php

namespace Samsara\Fermat\Provider\Stats\Distribution;

use RandomLib\Factory;
use Samsara\Exceptions\UsageError\OptionalExit;
use Samsara\Fermat\Numbers;
use Samsara\Fermat\Provider\Stats\Stats;
use Samsara\Fermat\Types\Base\NumberInterface;
use Samsara\Fermat\Values\ImmutableNumber;

class Normal
{

    /**
     * @var ImmutableNumber
     */
    private $mean;

    /**
     * @var ImmutableNumber
     */
    private $sd;

    public function __construct($mean, $sd)
    {
        $mean = Numbers::makeOrDont(Numbers::IMMUTABLE, $mean);
        $sd = Numbers::makeOrDont(Numbers::IMMUTABLE, $sd);

        $this->mean = $mean;

        $this->sd = $sd;

    }

    public static function makeFromMean($p, $x, $mean)

    {
        $one = Numbers::makeOne();
        $p = Numbers::makeOrDont(Numbers::IMMUTABLE, $p);
        $x = Numbers::makeOrDont(Numbers::IMMUTABLE, $x);
        $mean = Numbers::makeOrDont(Numbers::IMMUTABLE, $mean);

        $z = Stats::inverseNormalCDF($one->subtract($p));

        $sd = $x->subtract($mean)->divide($z);

        return new Normal($mean, $sd);
    }

    public static function makeFromSd($p, $x, $sd)

    {
        $one = Numbers::makeOne();
        $p = Numbers::makeOrDont(Numbers::IMMUTABLE, $p);
        $x = Numbers::makeOrDont(Numbers::IMMUTABLE, $x);
        $sd = Numbers::makeOrDont(Numbers::IMMUTABLE, $sd);

        $z = Stats::inverseNormalCDF($one->subtract($p));

        $mean = $x->subtract($z->multiply($sd));

        return new Normal($mean, $sd);
    }
    
    public function cdf($x)
    {
        $x = Numbers::makeOrDont(Numbers::IMMUTABLE, $x);

        if (
            function_exists('stats_cdf_normal') &&
            $x->isLessThanOrEqualTo(PHP_INT_MAX) &&
            $x->isGreaterThanOrEqualTo(PHP_INT_MIN) &&
            $this->mean->isLessThanOrEqualTo(PHP_INT_MAX) &&
            $this->mean->isGreaterThanOrEqualTo(PHP_INT_MIN) &&
            $this->sd->isLessThanOrEqualTo(PHP_INT_MAX) &&
            $this->sd->isGreaterThanOrEqualTo(PHP_INT_MIN)
        ) {
            return Numbers::make(Numbers::IMMUTABLE, stats_cdf_normal($x->getValue(), $this->mean, $this->sd));
        }

        $oneHalf = Numbers::make(Numbers::IMMUTABLE, '0.5');
        $one = Numbers::makeOne();
        $sqrtTwo = Numbers::make(Numbers::IMMUTABLE, 2)->sqrt();

        return $oneHalf->multiply($one->add(Stats::gaussErrorFunction(
            $x->subtract($this->mean)->divide($this->sd->multiply($sqrtTwo))
        )));
    }
    
    public function pdf($x1, $x2 = null)
    {

        $x1 = Numbers::makeOrDont(Numbers::IMMUTABLE, $x1);

        if (is_null($x2)) {
            $separation = $x1->subtract($this->mean)->multiply(2)->abs();

            if ($this->mean->isLessThan($x1)) {
                $x2 = $x1->subtract($separation);
            } else {
                $x2 = $x1->add($separation);
            }
        }

        return $this->cdf($x1)->subtract($this->cdf($x2))->abs();
    }

    public function percentBelowX($x)
    {
        return $this->cdf($x);
    }

    public function percentAboveX($x)
    {
        $one = Numbers::makeOne();

        return $one->subtract($this->cdf($x));
    }

    public function zScoreOfX($x)
    {
        $x = Numbers::makeOrDont(Numbers::IMMUTABLE, $x);

        return $x->subtract($this->mean)->divide($this->sd);
    }

    public function xFromZScore($z)
    {
        $z = Numbers::makeOrDont(Numbers::IMMUTABLE, $z);

        return $z->multiply($this->sd)->add($this->mean);
    }

    /**
     * @return ImmutableNumber
     */
    public function random()
    {
        if (
            function_exists('stats_rand_gen_normal') &&
            $this->mean->isLessThanOrEqualTo(PHP_INT_MAX) &&
            $this->mean->isGreaterThanOrEqualTo(PHP_INT_MIN) &&
            $this->sd->isLessThanOrEqualTo(PHP_INT_MAX) &&
            $this->sd->isGreaterThanOrEqualTo(PHP_INT_MIN)
        ) {
            return Numbers::make(Numbers::IMMUTABLE, stats_rand_gen_normal($this->mean, $this->sd), 20);
        } else {
            $randFactory = new Factory();
            $generator = $randFactory->getMediumStrengthGenerator();

            $rand1 = Numbers::make(Numbers::IMMUTABLE, $generator->generateInt(), 20);
            $rand1 = $rand1->divide(PHP_INT_MAX);
            $rand2 = Numbers::make(Numbers::IMMUTABLE, $generator->generateInt(), 20);
            $rand2 = $rand2->divide(PHP_INT_MAX);

            $randomNumber = $rand1->ln()->multiply(-2)->sqrt()->multiply($rand2->multiply(Numbers::TAU)->cos(1, 2, 20));
interface User
{
    /** @return string */
    public function getPassword();
}

class MyUser implements User
{
    public function getPassword()
    {
        // return something
    }

    public function getDisplayName()
    {
        // return some name.
    }
}

class AuthSystem
{
    public function authenticate(User $user)
    {
        $this->logger->info(sprintf('Authenticating %s.', $user->getDisplayName()));
        // do something.
    }
}
            $randomNumber = $randomNumber->multiply($this->sd)->add($this->mean);

            return $randomNumber;
        }
    }

    /**
     * @param int|float|NumberInterface $min
     * @param int|float|NumberInterface $max
     * @param int $maxIterations
     *
     * @return ImmutableNumber
     * @throws OptionalExit
     */
    public function rangeRandom($min = 0, $max = PHP_INT_MAX, $maxIterations = 20)

    {
        $i = 0;

        do {
            $randomNumber = $this->random();
            $i++;
        } while (($randomNumber->isGreaterThanOrEqualTo($max) || $randomNumber->isLessThanOrEqualTo($min)) && $i < $maxIterations);

        if ($randomNumber->isGreaterThan($max) || $randomNumber->isLessThan($min)) {
            throw new OptionalExit(
                'All random numbers generated were outside of the requested range',
                'A suitable random number, restricted by the $max ('.$max.') and $min ('.$min.'), could not be found within '.$maxIterations.' iterations'
            );
        } else {
            return $randomNumber;
        }
    }

}

1		<?php
2
3		namespace Samsara\Fermat\Provider\Stats\Distribution;
4
5		use RandomLib\Factory;
6		use Samsara\Exceptions\UsageError\OptionalExit;
7		use Samsara\Fermat\Numbers;
8		use Samsara\Fermat\Provider\Stats\Stats;
9		use Samsara\Fermat\Types\Base\NumberInterface;
10		use Samsara\Fermat\Values\ImmutableNumber;
11
12		class Normal
13		{
14
15		/**
16		* @var ImmutableNumber
17		*/
18		private $mean;
19
20		/**
21		* @var ImmutableNumber
22		*/
23		private $sd;
24
25		public function __construct($mean, $sd)
26		{
27		$mean = Numbers::makeOrDont(Numbers::IMMUTABLE, $mean);
28		$sd = Numbers::makeOrDont(Numbers::IMMUTABLE, $sd);
29
30		$this->mean = $mean;
		0 ignored issues – show Documentation Bug introduced 2017-01-11 07:39 UTC by Report Bug Copy Issue Report It seems like `$mean` of type `object<Samsara\Fermat\Types\Base\NumberInterface>` or `array` is incompatible with the declared type `object<Samsara\Fermat\Values\ImmutableNumber>` of property `$mean`. 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...
31		$this->sd = $sd;
		0 ignored issues – show Documentation Bug introduced 2017-01-11 07:39 UTC by Report Bug Copy Issue Report It seems like `$sd` of type `object<Samsara\Fermat\Types\Base\NumberInterface>` or `array` is incompatible with the declared type `object<Samsara\Fermat\Values\ImmutableNumber>` of property `$sd`. Our type inference engine has found an assignment to a property that is incompatible with the declared type of that property. Either this assignment is in error or the assigned type should be added to the documentation/type hint for that property.. Loading history...
32		}
33
34	View Code Duplication	public static function makeFromMean($p, $x, $mean)
		0 ignored issues – show Duplication introduced 2016-11-07 23:46 UTC by Report Bug Copy Issue Report This method seems to be duplicated in your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
35		{
36		$one = Numbers::makeOne();
37		$p = Numbers::makeOrDont(Numbers::IMMUTABLE, $p);
38		$x = Numbers::makeOrDont(Numbers::IMMUTABLE, $x);
39		$mean = Numbers::makeOrDont(Numbers::IMMUTABLE, $mean);
40
41		$z = Stats::inverseNormalCDF($one->subtract($p));
42
43		$sd = $x->subtract($mean)->divide($z);
44
45		return new Normal($mean, $sd);
46		}
47
48	View Code Duplication	public static function makeFromSd($p, $x, $sd)
		0 ignored issues – show Duplication introduced 2016-11-07 23:46 UTC by Report Bug Copy Issue Report This method seems to be duplicated in your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
49		{
50		$one = Numbers::makeOne();
51		$p = Numbers::makeOrDont(Numbers::IMMUTABLE, $p);
52		$x = Numbers::makeOrDont(Numbers::IMMUTABLE, $x);
53		$sd = Numbers::makeOrDont(Numbers::IMMUTABLE, $sd);
54
55		$z = Stats::inverseNormalCDF($one->subtract($p));
56
57		$mean = $x->subtract($z->multiply($sd));
58
59		return new Normal($mean, $sd);
60		}
61
62		public function cdf($x)
63		{
64		$x = Numbers::makeOrDont(Numbers::IMMUTABLE, $x);
65
66		if (
67		function_exists('stats_cdf_normal') &&
68		$x->isLessThanOrEqualTo(PHP_INT_MAX) &&
69		$x->isGreaterThanOrEqualTo(PHP_INT_MIN) &&
70		$this->mean->isLessThanOrEqualTo(PHP_INT_MAX) &&
71		$this->mean->isGreaterThanOrEqualTo(PHP_INT_MIN) &&
72		$this->sd->isLessThanOrEqualTo(PHP_INT_MAX) &&
73		$this->sd->isGreaterThanOrEqualTo(PHP_INT_MIN)
74		) {
75		return Numbers::make(Numbers::IMMUTABLE, stats_cdf_normal($x->getValue(), $this->mean, $this->sd));
76		}
77
78		$oneHalf = Numbers::make(Numbers::IMMUTABLE, '0.5');
79		$one = Numbers::makeOne();
80		$sqrtTwo = Numbers::make(Numbers::IMMUTABLE, 2)->sqrt();
81
82		return $oneHalf->multiply($one->add(Stats::gaussErrorFunction(
83		$x->subtract($this->mean)->divide($this->sd->multiply($sqrtTwo))
84		)));
85		}
86
87		public function pdf($x1, $x2 = null)
88		{
89
90		$x1 = Numbers::makeOrDont(Numbers::IMMUTABLE, $x1);
91
92		if (is_null($x2)) {
93		$separation = $x1->subtract($this->mean)->multiply(2)->abs();
94
95		if ($this->mean->isLessThan($x1)) {
96		$x2 = $x1->subtract($separation);
97		} else {
98		$x2 = $x1->add($separation);
99		}
100		}
101
102		return $this->cdf($x1)->subtract($this->cdf($x2))->abs();
103		}
104
105		public function percentBelowX($x)
106		{
107		return $this->cdf($x);
108		}
109
110		public function percentAboveX($x)
111		{
112		$one = Numbers::makeOne();
113
114		return $one->subtract($this->cdf($x));
115		}
116
117		public function zScoreOfX($x)
118		{
119		$x = Numbers::makeOrDont(Numbers::IMMUTABLE, $x);
120
121		return $x->subtract($this->mean)->divide($this->sd);
122		}
123
124		public function xFromZScore($z)
125		{
126		$z = Numbers::makeOrDont(Numbers::IMMUTABLE, $z);
127
128		return $z->multiply($this->sd)->add($this->mean);
129		}
130
131		/**
132		* @return ImmutableNumber
133		*/
134		public function random()
135		{
136		if (
137		function_exists('stats_rand_gen_normal') &&
138		$this->mean->isLessThanOrEqualTo(PHP_INT_MAX) &&
139		$this->mean->isGreaterThanOrEqualTo(PHP_INT_MIN) &&
140		$this->sd->isLessThanOrEqualTo(PHP_INT_MAX) &&
141		$this->sd->isGreaterThanOrEqualTo(PHP_INT_MIN)
142		) {
143		return Numbers::make(Numbers::IMMUTABLE, stats_rand_gen_normal($this->mean, $this->sd), 20);
144		} else {
145		$randFactory = new Factory();
146		$generator = $randFactory->getMediumStrengthGenerator();
147
148		$rand1 = Numbers::make(Numbers::IMMUTABLE, $generator->generateInt(), 20);
149		$rand1 = $rand1->divide(PHP_INT_MAX);
150		$rand2 = Numbers::make(Numbers::IMMUTABLE, $generator->generateInt(), 20);
151		$rand2 = $rand2->divide(PHP_INT_MAX);
152
153		$randomNumber = $rand1->ln()->multiply(-2)->sqrt()->multiply($rand2->multiply(Numbers::TAU)->cos(1, 2, 20));
		0 ignored issues – show Bug introduced 2017-01-09 19:42 UTC by Report Bug Copy Issue Report It seems like you code against a concrete implementation and not the interface `Samsara\Fermat\Types\Base\NumberInterface` as the method `cos()` does only exist in the following implementations of said interface: `Samsara\Fermat\Values\Currency`, `Samsara\Fermat\Values\ImmutableNumber`, `Samsara\Fermat\Values\MutableNumber`. Let’s take a look at an example: interface User { /** @return string / public function getPassword(); } class MyUser implements User { public function getPassword() { // return something } public function getDisplayName() { // return some name. } } class AuthSystem { public function authenticate(User $user) { $this->logger->info(sprintf('Authenticating %s.', $user->getDisplayName())); // do something. } } In the above example, the authenticate() method works fine as long as you just pass instances of MyUser. However, if you now also want to pass a different implementation of User which does not have a getDisplayName() method, the code will break. Available Fixes Change the type-hint for the parameter: class AuthSystem { public function authenticate(MyUser $user) { / ... / } } Add an additional type-check: class AuthSystem { public function authenticate(User $user) { if ($user instanceof MyUser) { $this->logger->info(/* ... /); } // or alternatively if ( ! $user instanceof MyUser) { throw new \LogicException( '$user must be an instance of MyUser, ' .'other instances are not supported.' ); } } } Note:* PHP Analyzer uses reverse abstract interpretation to narrow down the types inside the if block in such a case. Add the method to the interface: interface User { /** @return string / public function getPassword(); /* @return string */ public function getDisplayName(); } Loading history...
154		$randomNumber = $randomNumber->multiply($this->sd)->add($this->mean);
155
156		return $randomNumber;
157		}
158		}
159
160		/**
161		* @param int\|float\|NumberInterface $min
162		* @param int\|float\|NumberInterface $max
163		* @param int $maxIterations
164		*
165		* @return ImmutableNumber
166		* @throws OptionalExit
167		*/
168	View Code Duplication	public function rangeRandom($min = 0, $max = PHP_INT_MAX, $maxIterations = 20)
		0 ignored issues – show Duplication introduced 2017-01-11 07:39 UTC by Report Bug Copy Issue Report This method seems to be duplicated in your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
169		{
170		$i = 0;
171
172		do {
173		$randomNumber = $this->random();
174		$i++;
175		} while (($randomNumber->isGreaterThanOrEqualTo($max) \|\| $randomNumber->isLessThanOrEqualTo($min)) && $i < $maxIterations);
176
177		if ($randomNumber->isGreaterThan($max) \|\| $randomNumber->isLessThan($min)) {
178		throw new OptionalExit(
179		'All random numbers generated were outside of the requested range',
180		'A suitable random number, restricted by the $max ('.$max.') and $min ('.$min.'), could not be found within '.$maxIterations.' iterations'
181		);
182		} else {
183		return $randomNumber;
184		}
185		}
186
187		}

JordanRL / Fermat

Push — dev ( 021c9f...a2bcd2 )

Normal::xFromZScore() A

Complexity

Size

Duplication

Importance

Available Fixes

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