libstdc++-v3/testsuite/26_numerics/random/piecewise_linear_distribution/cons/num_xbound_fun.cc

   1 // { dg-options "-std=c++0x" }
   2 //
   3 // 2008-12-03  Edward M. Smith-Rowland <3dw4rd@verizon.net>
   4 //
   5 // Copyright (C) 2008, 2009 Free Software Foundation, Inc.
   6 //
   7 // This file is part of the GNU ISO C++ Library.  This library is free
   8 // software; you can redistribute it and/or modify it under the
   9 // terms of the GNU General Public License as published by the
  10 // Free Software Foundation; either version 3, or (at your option)
  11 // any later version.
  12 //
  13 // This library is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17 //
  18 // You should have received a copy of the GNU General Public License along
  19 // with this library; see the file COPYING3.  If not see
  20 // <http://www.gnu.org/licenses/>.
  21
  22 // 26.4.8.5.3 Class template piecewise_linear_distribution [rand.dist.samp.plinear]
  23 // 26.4.2.4 Concept RandomNumberDistribution [rand.concept.dist]
  24
  25 #include <random>
  26 #include <cmath>
  27 #include <testsuite_hooks.h>
  28
  29 struct cosine_distribution
  30 {
  31     cosine_distribution(double x0, double lambda)
  32     : _M_x0(x0), _M_lambda(lambda)
  33     { }
  34
  35     double
  36     operator()(double x)
  37     {
  38       if (x - _M_x0 < -_M_lambda / 4)
  39         return 0.0;
  40       else if (x - _M_x0 > _M_lambda / 4)
  41         return 0.0;
  42       else
  43         return std::cos(2 * M_PI * (x - _M_x0) / _M_lambda);
  44     }
  45
  46 private:
  47     double _M_x0;
  48     double _M_lambda;
  49 };
  50
  51 void
  52 test01()
  53 {
  54   bool test __attribute__((unused)) = true;
  55
  56   cosine_distribution cd(1.5, 3.0);
  57   std::piecewise_linear_distribution<> u(21, -10.0, 10.0, cd);
  58   std::vector<double> interval = u.intervals();
  59   std::vector<double> density = u.densities();
  60   VERIFY( interval.size() == 22 );
  61   VERIFY( density.size() == 22 );
  62 }
  63
  64 int main()
  65 {
  66   test01();
  67   return 0;
  68 }