Exponential::cdf() - 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

Exponential::cdf() B

↳ Parent: Exponential

Complexity

Conditions	5
Paths	3

Size

Total Lines	32
Code Lines	16

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
dl	0
loc	32
rs	8.439
c	0
b	0
f	0
cc	5
eloc	16
nc	3
nop	1

<?php

namespace Samsara\Fermat\Provider\Stats\Distribution;

use RandomLib\Factory;
use Samsara\Exceptions\UsageError\IntegrityConstraint;
use Samsara\Exceptions\UsageError\OptionalExit;
use Samsara\Fermat\Numbers;
use Samsara\Fermat\Types\Base\DecimalInterface;
use Samsara\Fermat\Values\ImmutableNumber;

class Exponential
{

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

    /**
     * Exponential constructor.
     *
     * @param int|float|DecimalInterface $lambda This is the *rate parameter* not the *scale parameter*
     *
     * @throws IntegrityConstraint
     */
    public function __construct($lambda)

    {
        $lambda = Numbers::makeOrDont(Numbers::IMMUTABLE, $lambda);
/**
 * @return array|string
 */
function returnsDifferentValues($x) {
    if ($x) {
        return 'foo';
    }

    return array();
}

$x = returnsDifferentValues($y);
if (is_array($x)) {
    // $x is an array.
}

        if (!$lambda->isPositive()) {
            throw new IntegrityConstraint(
                'Lambda must be positive',
                'Provide a positive lambda',
                'Exponential distributions work on time to occurrence; the mean time to occurrence (lambda) must be positive'
            );
        }

        $this->lambda = $lambda;

    }

    /**
     * @param int|float|DecimalInterface $x
     *
     * @return ImmutableNumber
     * @throws IntegrityConstraint
     */
    public function cdf($x)
    {

        $x = Numbers::makeOrDont(Numbers::IMMUTABLE, $x);
/**
 * @return array|string
 */
function returnsDifferentValues($x) {
    if ($x) {
        return 'foo';
    }

    return array();
}

$x = returnsDifferentValues($y);
if (is_array($x)) {
    // $x is an array.
}

        if (!$x->isPositive()) {
            throw new IntegrityConstraint(
                'X must be positive',
                'Provide a positive x',
                'Exponential distributions work on time to occurrence; the time to occurrence (x) must be positive'
            );
        }

        if (
            function_exists('stats_cdf_exponential') &&
            $x->isLessThanOrEqualTo(PHP_INT_MAX) &&
            $this->lambda->isLessThanOrEqualTo(PHP_INT_MAX)
        ) {
            return Numbers::make(Numbers::IMMUTABLE, stats_cdf_exponential($x->getValue(), $this->lambda->getValue(), 1));
        }

        /** @var ImmutableNumber $one */
        $one = Numbers::makeOne();
        /** @var ImmutableNumber $e */
        $e = Numbers::makeE();

        /** @var ImmutableNumber $cdf */
        $cdf = $one->subtract($e->pow($x->multiply($this->lambda)->multiply(-1)));

        return $cdf;

    }

    /**
     * @param $x
     *
     * @return ImmutableNumber
     * @throws IntegrityConstraint
     */
    public function pdf($x)

    {

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

        if (!$x->isPositive()) {
            throw new IntegrityConstraint(
                'X must be positive',
                'Provide a positive x',
                'Exponential distributions work on time to occurrence; the time to occurrence (x) must be positive'
            );
        }

        if (
            function_exists('stats_dens_exponential') &&
            $x->isLessThanOrEqualTo(PHP_INT_MAX) &&
            $this->lambda->isLessThanOrEqualTo(PHP_INT_MAX)
        ) {
            return Numbers::make(Numbers::IMMUTABLE, stats_dens_exponential($x->getValue(), $this->lambda->pow(-1)->getValue()));
        }

        /** @var ImmutableNumber $e */
        $e = Numbers::makeE();

        /** @var ImmutableNumber $pdf */
        $pdf = $this->lambda->multiply($e->pow($this->lambda->multiply(-1)->multiply($x)));

        return $pdf;

    }

    /**
     * @param $x1
     * @param $x2
     *
     * @return ImmutableNumber
     * @throws IntegrityConstraint
     */
    public function rangePdf($x1, $x2)
    {
        $x1 = Numbers::makeOrDont(Numbers::IMMUTABLE, $x1);
        $x2 = Numbers::makeOrDont(Numbers::IMMUTABLE, $x2);
        $one = Numbers::makeOne();

        if (!$x1->isPositive() || !$x2->isPositive()) {
            throw new IntegrityConstraint(
                'X must be positive',
                'Provide a positive x',
                'Exponential distributions work on time to occurrence; the time to occurrence (x) must be positive'
            );
        }

        if (
            function_exists('stats_dens_exponential') &&
            $x1->isLessThanOrEqualTo(PHP_INT_MAX) &&
            $x2->isLessThanOrEqualTo(PHP_INT_MAX) &&
            $this->lambda->isLessThanOrEqualTo(PHP_INT_MAX)
        ) {
            /** @var ImmutableNumber $pdf1 */
            $pdf1 = Numbers::make(Numbers::IMMUTABLE, stats_dens_exponential($x1->getValue(), $one->divide($this->lambda)->getValue()));
            /** @var ImmutableNumber $pdf2 */
            $pdf2 = Numbers::make(Numbers::IMMUTABLE, stats_dens_exponential($x2->getValue(), $one->divide($this->lambda)->getValue()));

            /** @var ImmutableNumber $rangePdf */
            $rangePdf = $pdf1->subtract($pdf2)->abs();

            return $rangePdf;
        }

        /** @var ImmutableNumber $rangePdf */
        $rangePdf = $this->pdf($x2)->subtract($this->pdf($x1))->abs();

        return $rangePdf;
    }

    /**
     * @return ImmutableNumber
     */
    public function random()
    {

        $randFactory = new Factory();
        $generator = $randFactory->getMediumStrengthGenerator();
        $one = Numbers::makeOne();
        $u = $generator->generateInt() / PHP_INT_MAX;

        /** @var ImmutableNumber $random */
        $random = $one->subtract($u)->ln()->divide($this->lambda->multiply(-1));
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.
    }
}

        return $random;

    }

    /**
     * @param int|float|DecimalInterface $min
     * @param int|float|DecimalInterface $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\IntegrityConstraint;
7		use Samsara\Exceptions\UsageError\OptionalExit;
8		use Samsara\Fermat\Numbers;
9		use Samsara\Fermat\Types\Base\DecimalInterface;
10		use Samsara\Fermat\Values\ImmutableNumber;
11
12		class Exponential
13		{
14
15		/**
16		* @var ImmutableNumber
17		*/
18		private $lambda;
19
20		/**
21		* Exponential constructor.
22		*
23		* @param int\|float\|DecimalInterface $lambda This is the rate parameter not the scale parameter
24		*
25		* @throws IntegrityConstraint
26		*/
27	View Code Duplication	public function __construct($lambda)
		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...
28		{
29		$lambda = Numbers::makeOrDont(Numbers::IMMUTABLE, $lambda);
		0 ignored issues – show Bug introduced 2017-01-11 07:39 UTC by Report Bug Copy Issue Report It seems like `$lambda` defined by `\Samsara\Fermat\Numbers:...rs::IMMUTABLE, $lambda)` on line `29` can also be of type `object<Samsara\Fermat\Ty...\Base\DecimalInterface>`; however, `Samsara\Fermat\Numbers::makeOrDont()` does only seem to accept `integer\|double\|string\|ob...s\Base\NumberInterface>`, maybe add an additional type check? If a method or function can return multiple different values and unless you are sure that you only can receive a single value in this context, we recommend to add an additional type check: /** * @return array\|string */ function returnsDifferentValues($x) { if ($x) { return 'foo'; } return array(); } $x = returnsDifferentValues($y); if (is_array($x)) { // $x is an array. } If this a common case that PHP Analyzer should handle natively, please let us know by opening an issue. Loading history...
30
31		if (!$lambda->isPositive()) {
32		throw new IntegrityConstraint(
33		'Lambda must be positive',
34		'Provide a positive lambda',
35		'Exponential distributions work on time to occurrence; the mean time to occurrence (lambda) must be positive'
36		);
37		}
38
39		$this->lambda = $lambda;
		0 ignored issues – show Documentation Bug introduced 2017-01-11 07:39 UTC by Report Bug Copy Issue Report It seems like `$lambda` of type `object<Samsara\Fermat\Types\Base\NumberInterface>` or `array` is incompatible with the declared type `object<Samsara\Fermat\Values\ImmutableNumber>` of property `$lambda`. 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...
40		}
41
42		/**
43		* @param int\|float\|DecimalInterface $x
44		*
45		* @return ImmutableNumber
46		* @throws IntegrityConstraint
47		*/
48		public function cdf($x)
49		{
50
51		$x = Numbers::makeOrDont(Numbers::IMMUTABLE, $x);
		0 ignored issues – show Bug introduced 2017-01-11 07:39 UTC by Report Bug Copy Issue Report It seems like `$x` defined by `\Samsara\Fermat\Numbers:...Numbers::IMMUTABLE, $x)` on line `51` can also be of type `object<Samsara\Fermat\Ty...\Base\DecimalInterface>`; however, `Samsara\Fermat\Numbers::makeOrDont()` does only seem to accept `integer\|double\|string\|ob...s\Base\NumberInterface>`, maybe add an additional type check? If a method or function can return multiple different values and unless you are sure that you only can receive a single value in this context, we recommend to add an additional type check: /** * @return array\|string */ function returnsDifferentValues($x) { if ($x) { return 'foo'; } return array(); } $x = returnsDifferentValues($y); if (is_array($x)) { // $x is an array. } If this a common case that PHP Analyzer should handle natively, please let us know by opening an issue. Loading history...
52
53		if (!$x->isPositive()) {
54		throw new IntegrityConstraint(
55		'X must be positive',
56		'Provide a positive x',
57		'Exponential distributions work on time to occurrence; the time to occurrence (x) must be positive'
58		);
59		}
60
61		if (
62		function_exists('stats_cdf_exponential') &&
63		$x->isLessThanOrEqualTo(PHP_INT_MAX) &&
64		$this->lambda->isLessThanOrEqualTo(PHP_INT_MAX)
65		) {
66		return Numbers::make(Numbers::IMMUTABLE, stats_cdf_exponential($x->getValue(), $this->lambda->getValue(), 1));
67		}
68
69		/** @var ImmutableNumber $one */
70		$one = Numbers::makeOne();
71		/** @var ImmutableNumber $e */
72		$e = Numbers::makeE();
73
74		/** @var ImmutableNumber $cdf */
75		$cdf = $one->subtract($e->pow($x->multiply($this->lambda)->multiply(-1)));
76
77		return $cdf;
78
79		}
80
81		/**
82		* @param $x
83		*
84		* @return ImmutableNumber
85		* @throws IntegrityConstraint
86		*/
87	View Code Duplication	public function pdf($x)
		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...
88		{
89
90		$x = Numbers::makeOrDont(Numbers::IMMUTABLE, $x);
91
92		if (!$x->isPositive()) {
93		throw new IntegrityConstraint(
94		'X must be positive',
95		'Provide a positive x',
96		'Exponential distributions work on time to occurrence; the time to occurrence (x) must be positive'
97		);
98		}
99
100		if (
101		function_exists('stats_dens_exponential') &&
102		$x->isLessThanOrEqualTo(PHP_INT_MAX) &&
103		$this->lambda->isLessThanOrEqualTo(PHP_INT_MAX)
104		) {
105		return Numbers::make(Numbers::IMMUTABLE, stats_dens_exponential($x->getValue(), $this->lambda->pow(-1)->getValue()));
106		}
107
108		/** @var ImmutableNumber $e */
109		$e = Numbers::makeE();
110
111		/** @var ImmutableNumber $pdf */
112		$pdf = $this->lambda->multiply($e->pow($this->lambda->multiply(-1)->multiply($x)));
113
114		return $pdf;
115
116		}
117
118		/**
119		* @param $x1
120		* @param $x2
121		*
122		* @return ImmutableNumber
123		* @throws IntegrityConstraint
124		*/
125		public function rangePdf($x1, $x2)
126		{
127		$x1 = Numbers::makeOrDont(Numbers::IMMUTABLE, $x1);
128		$x2 = Numbers::makeOrDont(Numbers::IMMUTABLE, $x2);
129		$one = Numbers::makeOne();
130
131		if (!$x1->isPositive() \|\| !$x2->isPositive()) {
132		throw new IntegrityConstraint(
133		'X must be positive',
134		'Provide a positive x',
135		'Exponential distributions work on time to occurrence; the time to occurrence (x) must be positive'
136		);
137		}
138
139		if (
140		function_exists('stats_dens_exponential') &&
141		$x1->isLessThanOrEqualTo(PHP_INT_MAX) &&
142		$x2->isLessThanOrEqualTo(PHP_INT_MAX) &&
143		$this->lambda->isLessThanOrEqualTo(PHP_INT_MAX)
144		) {
145		/** @var ImmutableNumber $pdf1 */
146		$pdf1 = Numbers::make(Numbers::IMMUTABLE, stats_dens_exponential($x1->getValue(), $one->divide($this->lambda)->getValue()));
147		/** @var ImmutableNumber $pdf2 */
148		$pdf2 = Numbers::make(Numbers::IMMUTABLE, stats_dens_exponential($x2->getValue(), $one->divide($this->lambda)->getValue()));
149
150		/** @var ImmutableNumber $rangePdf */
151		$rangePdf = $pdf1->subtract($pdf2)->abs();
152
153		return $rangePdf;
154		}
155
156		/** @var ImmutableNumber $rangePdf */
157		$rangePdf = $this->pdf($x2)->subtract($this->pdf($x1))->abs();
158
159		return $rangePdf;
160		}
161
162		/**
163		* @return ImmutableNumber
164		*/
165		public function random()
166		{
167
168		$randFactory = new Factory();
169		$generator = $randFactory->getMediumStrengthGenerator();
170		$one = Numbers::makeOne();
171		$u = $generator->generateInt() / PHP_INT_MAX;
172
173		/** @var ImmutableNumber $random */
174		$random = $one->subtract($u)->ln()->divide($this->lambda->multiply(-1));
		0 ignored issues – show Bug introduced 2017-01-11 07:39 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 `ln()` 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...
175
176		return $random;
177
178		}
179
180		/**
181		* @param int\|float\|DecimalInterface $min
182		* @param int\|float\|DecimalInterface $max
183		* @param int $maxIterations
184		*
185		* @return ImmutableNumber
186		* @throws OptionalExit
187		*/
188	View Code Duplication	public function rangeRandom($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...
189		{
190
191		$i = 0;
192
193		do {
194		$randomNumber = $this->random();
195		$i++;
196		} while (($randomNumber->isGreaterThanOrEqualTo($max) \|\| $randomNumber->isLessThanOrEqualTo($min)) && $i < $maxIterations);
197
198		if ($randomNumber->isGreaterThan($max) \|\| $randomNumber->isLessThan($min)) {
199		throw new OptionalExit(
200		'All random numbers generated were outside of the requested range',
201		'A suitable random number, restricted by the $max ('.$max.') and $min ('.$min.'), could not be found within '.$maxIterations.' iterations'
202		);
203		} else {
204		return $randomNumber;
205		}
206
207		}
208
209		}

JordanRL / Fermat

Push — dev ( 021c9f...a2bcd2 )

Exponential::cdf() B

Complexity

Size

Duplication

Importance

Available Fixes

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