1<?php
2
3/**
4 * Hoa
5 *
6 *
7 * @license
8 *
9 * New BSD License
10 *
11 * Copyright © 2007-2017, Hoa community. All rights reserved.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions are met:
15 *     * Redistributions of source code must retain the above copyright
16 *       notice, this list of conditions and the following disclaimer.
17 *     * Redistributions in binary form must reproduce the above copyright
18 *       notice, this list of conditions and the following disclaimer in the
19 *       documentation and/or other materials provided with the distribution.
20 *     * Neither the name of the Hoa nor the names of its contributors may be
21 *       used to endorse or promote products derived from this software without
22 *       specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
25 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS AND CONTRIBUTORS BE
28 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34 * POSSIBILITY OF SUCH DAMAGE.
35 */
36
37namespace Hoa\Math\Sampler;
38
39/**
40 * Class \Hoa\Math\Sampler\Random.
41 *
42 * Random sampler.
43 *
44 * @copyright  Copyright © 2007-2017 Hoa community
45 * @license    New BSD License
46 */
47class Random extends Sampler
48{
49    /**
50     * Construct.
51     *
52     * @return  void
53     */
54    public function construct()
55    {
56        if (null === $this->_parameters->getParameter('integer.min')) {
57            $this->_parameters->setParameter(
58                'integer.min',
59                max(
60                    -mt_getrandmax(),
61                    $this->_parameters->getParameter('integer.min')
62                )
63            );
64        }
65
66        if (null === $this->_parameters->getParameter('integer.max')) {
67            $this->_parameters->setParameter(
68                'integer.max',
69                min(
70                    mt_getrandmax(),
71                    $this->_parameters->getParameter('integer.max')
72                )
73            );
74        }
75
76        return;
77    }
78
79    /**
80     * Generate a discrete uniform distribution.
81     *
82     * @param   int  $lower    Lower bound value.
83     * @param   int  $upper    Upper bound value.
84     * @return  int
85     */
86    protected function _getInteger($lower, $upper)
87    {
88        return mt_rand($lower, $upper);
89    }
90
91    /**
92     * Generate a continuous uniform distribution.
93     *
94     * @param   float      $lower    Lower bound value.
95     * @param   float      $upper    Upper bound value.
96     * @return  float
97     */
98    protected function _getFloat($lower, $upper)
99    {
100        return $lower + lcg_value() * abs($upper - $lower);
101    }
102}
103