ceph/src/boost/libs/math/example/policy_eg_7.cpp

   1 //  Copyright John Maddock 2007.
   2 //  Copyright Paul A. Bristow 2010
   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 // Note that this file contains quickbook mark-up as well as code
   8 // and comments, don't change any of the special comment mark-ups!
   9
  10 #include <iostream>
  11 using std::cout;  using std::endl;
  12 #include <cerrno> // for ::errno
  13
  14 //[policy_eg_7
  15
  16 #include <boost/math/distributions.hpp> // All distributions.
  17 // using boost::math::normal; // Would create an ambguity between
  18 // boost::math::normal_distribution<RealType> boost::math::normal and
  19 // 'anonymous-namespace'::normal'.
  20
  21 namespace
  22 { // anonymous or unnnamed (rather than named as in policy_eg_6.cpp).
  23
  24   using namespace boost::math::policies;
  25    // using boost::math::policies::errno_on_error; // etc.
  26   typedef policy<
  27      // return infinity and set errno rather than throw:
  28      overflow_error<errno_on_error>,
  29      // Don't promote double -> long double internally:
  30      promote_double<false>,
  31      // Return the closest integer result for discrete quantiles:
  32      discrete_quantile<integer_round_nearest>
  33   > my_policy;
  34
  35   BOOST_MATH_DECLARE_DISTRIBUTIONS(double, my_policy)
  36
  37 } // close namespace my_namespace
  38
  39 int main()
  40 {
  41    // Construct distribution with something we know will overflow.
  42    normal norm(10, 2); // using 'anonymous-namespace'::normal
  43    errno = 0;
  44    cout << "Result of quantile(norm, 0) is: "
  45       << quantile(norm, 0) << endl;
  46    cout << "errno = " << errno << endl;
  47    errno = 0;
  48    cout << "Result of quantile(norm, 1) is: "
  49       << quantile(norm, 1) << endl;
  50    cout << "errno = " << errno << endl;
  51    //
  52    // Now try a discrete distribution:
  53    binomial binom(20, 0.25);
  54    cout << "Result of quantile(binom, 0.05) is: "
  55       << quantile(binom, 0.05) << endl;
  56    cout << "Result of quantile(complement(binom, 0.05)) is: "
  57       << quantile(complement(binom, 0.05)) << endl;
  58 }
  59
  60 //] //[/policy_eg_7]
  61
  62 /*
  63
  64 Output:
  65
  66   Result of quantile(norm, 0) is: -1.#INF
  67   errno = 34
  68   Result of quantile(norm, 1) is: 1.#INF
  69   errno = 34
  70   Result of quantile(binom, 0.05) is: 1
  71   Result of quantile(complement(binom, 0.05)) is: 8
  72
  73 */