1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
|
.. Copyright (c) 2016, Johan Mabille, Sylvain Corlay and Wolf Vollprecht
Distributed under the terms of the BSD 3-Clause License.
The full license is in the file LICENSE, distributed with this software.
.. _random:
******
Random
******
:cpp:func:`xt::random::seed`
============================
Set seed for random number generator. A common practice to get a 'real' random number is to use:
.. code-block:: cpp
#include <ctime>
...
xt::random::seed(time(NULL));
:cpp:func:`xt::random::rand`
============================
:cpp:func:`xt::random::randint`
===============================
:cpp:func:`xt::random::randn`
=============================
:cpp:func:`xt::random::binomial`
================================
:cpp:func:`xt::random::geometric`
=================================
:cpp:func:`xt::random::negative_binomial`
=========================================
:cpp:func:`xt::random::poisson`
===============================
:cpp:func:`xt::random::exponential`
===================================
:cpp:func:`xt::random::gamma`
=============================
Produces (an array of) random positive floating-point values,
distributed according to the probability density:
.. math::
P(x) = x^{\alpha-1} \frac{e^{-x / \beta}}{\beta^\alpha \; \Gamma(\alpha)}
where :math:`\alpha` is the shape (also known as :math:`k`) and :math:`\beta` the scale
(also known as :math:`\theta`), and :math:`\Gamma` is the Gamma function.
.. note::
Different from NumPy, the first argument is the shape of the output array.
.. seealso::
* :any:`numpy.random.gamma`
* `std::gamma_distribution <https://en.cppreference.com/w/cpp/numeric/random/gamma_distribution>`_
* `Weisstein, Eric W. "Gamma Distribution." From MathWorld – A Wolfram Web Resource. <http://mathworld.wolfram.com/GammaDistribution.html>`_
* `Wikipedia, "Gamma distribution". <https://en.wikipedia.org/wiki/Gamma_distribution>`_
:cpp:func:`xt::random::weibull`
===============================
Produces (an array of) random positive floating-point values,
distributed according to the probability density:
.. math::
P(x) = \frac{a}{b} \left( \frac{x}{b} \right)^{a - 1} e^{-(x / b)^a}
where :math:`a > 0` is the shape parameter and :math:`b > 0` the scale parameter.
In particular, a random variable is produced as
.. math::
X = b (- \ln (U))^{1/a}
where :math:`U` is drawn from the uniform distribution (0, 1].
By default both the shape :math:`a = 1` and the scale :math:`b = 1`.
Note that you can specify only :math:`a` while choosing the default for :math:`b`.
.. note::
Different from NumPy, the first argument is the shape of the output array.
.. seealso::
* :any:`numpy.random.weibull`
* `std::weibull_distribution <https://en.cppreference.com/w/cpp/numeric/random/weibull_distribution>`_
* `Wikipedia, "Weibull distribution". <https://en.wikipedia.org/wiki/Weibull_distribution>`_
:cpp:func:`xt::random::extreme_value`
=====================================
:cpp:func:`xt::random::lognormal`
=================================
:cpp:func:`xt::random::cauchy`
==============================
:cpp:func:`xt::random::fisher_f`
================================
:cpp:func:`xt::random::student_t`
=================================
:cpp:func:`xt::random::choice`
==============================
:cpp:func:`xt::random::shuffle`
===============================
:cpp:func:`xt::random::permutation`
===================================
|
