1 // { dg-do run { target c++11 } }
2 // { dg-require-cstdint "" }
3 //
4 // 2008-12-03 Edward M. Smith-Rowland <3dw4rd@verizon.net>
5 //
6 // Copyright (C) 2008-2018 Free Software Foundation, Inc.
7 //
8 // This file is part of the GNU ISO C++ Library. This library is free
9 // software; you can redistribute it and/or modify it under the
10 // terms of the GNU General Public License as published by the
11 // Free Software Foundation; either version 3, or (at your option)
12 // any later version.
13 //
14 // This library is distributed in the hope that it will be useful,
15 // but WITHOUT ANY WARRANTY; without even the implied warranty of
16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 // GNU General Public License for more details.
18 //
19 // You should have received a copy of the GNU General Public License along
20 // with this library; see the file COPYING3. If not see
21 // <http://www.gnu.org/licenses/>.
22
23 // 26.4.8.5.3 Class template piecewise_linear_distribution
24 // [rand.dist.samp.plinear]
25 // 26.4.2.4 Concept RandomNumberDistribution [rand.concept.dist]
26
27 #include <random>
28 #include <cmath>
29 #include <testsuite_hooks.h>
30
31 struct cosine_distribution
32 {
cosine_distributioncosine_distribution33 cosine_distribution(double x0, double lambda)
34 : _M_x0(x0), _M_lambda(lambda)
35 { }
36
37 double
operator ()cosine_distribution38 operator()(double x)
39 {
40 if (x - _M_x0 < -_M_lambda / 4)
41 return 0.0;
42 else if (x - _M_x0 > _M_lambda / 4)
43 return 0.0;
44 else
45 {
46 const double pi = 3.14159265358979323846;
47 return std::cos(2 * pi * (x - _M_x0) / _M_lambda);
48 }
49 }
50
51 private:
52 double _M_x0;
53 double _M_lambda;
54 };
55
56 void
test01()57 test01()
58 {
59 cosine_distribution cd(1.5, 3.0);
60 std::piecewise_linear_distribution<> u({-10.0, -8.0, -6.0, -4.0, -2.0,
61 0.0, 2.0, 4.0, 6.0, 8.0, 10.0},
62 cd);
63 std::vector<double> interval = u.intervals();
64 std::vector<double> density = u.densities();
65 VERIFY( interval.size() == 11 );
66 VERIFY( density.size() == 11 );
67 }
68
main()69 int main()
70 {
71 test01();
72 return 0;
73 }
74