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) 2008-2021 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 // 26.4.8.5.1 Class template discrete_distribution [rand.dist.samp.discrete] 24 // 26.4.2.4 Concept RandomNumberDistribution [rand.concept.dist] 25 26 #include <random> 27 #include <cmath> 28 #include <testsuite_hooks.h> 29 30 struct cosine_distribution 31 { cosine_distributioncosine_distribution32 cosine_distribution(double x0, double lambda) 33 : _M_x0(x0), _M_lambda(lambda) 34 { } 35 36 double operator ()cosine_distribution37 operator()(double x) 38 { 39 if (x - _M_x0 < -_M_lambda / 4) 40 return 0.0; 41 else if (x - _M_x0 > _M_lambda / 4) 42 return 0.0; 43 else 44 { 45 const double pi = 3.14159265358979323846; 46 return std::cos(2 * pi * (x - _M_x0) / _M_lambda); 47 } 48 } 49 50 private: 51 double _M_x0; 52 double _M_lambda; 53 }; 54 55 void test01()56test01() 57 { 58 cosine_distribution cd(1.5, 3.0); 59 std::discrete_distribution<> u(21, -10.0, 10.0, cd); 60 std::vector<double> probablility = u.probabilities(); 61 VERIFY( probablility.size() == 21 ); 62 } 63 main()64int main() 65 { 66 test01(); 67 return 0; 68 } 69