ceph/src/boost/libs/math/test/cohen_acceleration_test.cpp

   1 /*
   2  * Copyright Nick Thompson, 2020
   3  * Use, modification and distribution are subject to the
   4  * Boost Software License, Version 1.0. (See accompanying file
   5  * LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6  */
   7
   8 #include "math_unit_test.hpp"
   9 #include <boost/math/tools/cohen_acceleration.hpp>
  10 #include <boost/math/constants/constants.hpp>
  11 #ifdef BOOST_HAS_FLOAT128
  12 #include <boost/multiprecision/float128.hpp>
  13 using boost::multiprecision::float128;
  14 #endif
  15 #include <boost/multiprecision/cpp_bin_float.hpp>
  16 #include <cmath>
  17
  18 using boost::math::tools::cohen_acceleration;
  19 using boost::multiprecision::cpp_bin_float_100;
  20 using boost::math::constants::pi;
  21 using std::log;
  22
  23 template<typename Real>
  24 class G {
  25 public:
  26     G(){
  27         k_ = 0;
  28     }
  29
  30     Real operator()() {
  31         k_ += 1;
  32         return 1/(k_*k_);
  33     }
  34
  35 private:
  36     Real k_;
  37 };
  38
  39 template<typename Real>
  40 void test_pisq_div12()
  41 {
  42     auto g = G<Real>();
  43     Real x = cohen_acceleration(g);
  44     CHECK_ULP_CLOSE(pi<Real>()*pi<Real>()/12, x, 3);
  45 }
  46
  47 template<typename Real>
  48 class Divergent {
  49 public:
  50     Divergent(){
  51         k_ = 0;
  52     }
  53
  54     // See C3 of: https://people.mpim-bonn.mpg.de/zagier/files/exp-math-9/fulltext.pdf
  55     Real operator()() {
  56         using std::log;
  57         k_ += 1;
  58         return log(k_);
  59     }
  60
  61 private:
  62     Real k_;
  63 };
  64
  65 template<typename Real>
  66 void test_divergent()
  67 {
  68     auto g = Divergent<Real>();
  69     Real x = -cohen_acceleration(g);
  70     CHECK_ULP_CLOSE(log(pi<Real>()/2)/2, x, 135);
  71 }
  72
  73 int main()
  74 {
  75     test_pisq_div12<float>();
  76     test_pisq_div12<double>();
  77     test_pisq_div12<long double>();
  78
  79     test_divergent<float>();
  80     test_divergent<double>();
  81     test_divergent<long double>();
  82
  83     #ifdef BOOST_HAS_FLOAT128
  84     test_pisq_div12<float128>();
  85     test_divergent<float128>();
  86     #endif
  87     return boost::math::test::report_errors();
  88 }