WSJT-X/boost/libs/math/example/policy_eg_7.cpp

74 lines
2.2 KiB
C++
Raw Normal View History

// Copyright John Maddock 2007.
// Copyright Paul A. Bristow 2010
// Use, modification and distribution are subject to the
// Boost Software License, Version 1.0. (See accompanying file
// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
// Note that this file contains quickbook mark-up as well as code
// and comments, don't change any of the special comment mark-ups!
#include <iostream>
using std::cout; using std::endl;
#include <cerrno> // for ::errno
//[policy_eg_7
#include <boost/math/distributions.hpp> // All distributions.
// using boost::math::normal; // Would create an ambguity between
// boost::math::normal_distribution<RealType> boost::math::normal and
// 'anonymous-namespace'::normal'.
namespace
{ // anonymous or unnnamed (rather than named as in policy_eg_6.cpp).
using namespace boost::math::policies;
// using boost::math::policies::errno_on_error; // etc.
typedef policy<
// return infinity and set errno rather than throw:
overflow_error<errno_on_error>,
// Don't promote double -> long double internally:
promote_double<false>,
// Return the closest integer result for discrete quantiles:
discrete_quantile<integer_round_nearest>
> my_policy;
BOOST_MATH_DECLARE_DISTRIBUTIONS(double, my_policy)
} // close namespace my_namespace
int main()
{
// Construct distribution with something we know will overflow.
normal norm(10, 2); // using 'anonymous-namespace'::normal
errno = 0;
cout << "Result of quantile(norm, 0) is: "
<< quantile(norm, 0) << endl;
cout << "errno = " << errno << endl;
errno = 0;
cout << "Result of quantile(norm, 1) is: "
<< quantile(norm, 1) << endl;
cout << "errno = " << errno << endl;
//
// Now try a discrete distribution:
binomial binom(20, 0.25);
cout << "Result of quantile(binom, 0.05) is: "
<< quantile(binom, 0.05) << endl;
cout << "Result of quantile(complement(binom, 0.05)) is: "
<< quantile(complement(binom, 0.05)) << endl;
}
//] //[/policy_eg_7]
/*
Output:
Result of quantile(norm, 0) is: -1.#INF
errno = 34
Result of quantile(norm, 1) is: 1.#INF
errno = 34
Result of quantile(binom, 0.05) is: 1
Result of quantile(complement(binom, 0.05)) is: 8
*/