math/test/pow_test.cpp

//  Boost pow_test.cpp test file
//  Tests the pow function

//  (C) Copyright Bruno Lalande 2008.
//  Distributed under 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)


#include <cmath>
#include <string>
#include <iostream>

#include <boost/math/concepts/real_concept.hpp>
#include <boost/test/included/test_exec_monitor.hpp>
#include <boost/test/floating_point_comparison.hpp>

#include <boost/typeof/typeof.hpp>
#include <boost/type_traits/is_same.hpp>
#include <boost/static_assert.hpp>

#include <boost/math/special_functions/pow.hpp>

#include BOOST_TYPEOF_INCREMENT_REGISTRATION_GROUP()
BOOST_TYPEOF_REGISTER_TYPE(boost::math::concepts::real_concept)

using namespace boost;
using namespace boost::math;

template <int N, class T>
void test_pow(T base)
{
    typedef typename tools::promote_args<T>::type result_type;

    BOOST_MATH_STD_USING

    if ((base == 0) && N < 0)
    {
       BOOST_CHECK_THROW(math::pow<N>(base), std::overflow_error);
    }
    else
    {
       BOOST_CHECK_CLOSE(math::pow<N>(base),
              pow(static_cast<result_type>(base), static_cast<result_type>(N)),
              boost::math::tools::epsilon<result_type>() * 100 * 200); // 200 eps as a %
    }
}

template <int N, class T>
void test_with_big_bases()
{
    for (T base = T(); base < T(1000); ++base)
        test_pow<N>(base);
}

template <int N, class T>
void test_with_small_bases()
{
    T base = 0.9f;
    for (int i = 0; i < 10; ++i)
    {
        base += base/50;
        test_pow<N>(base);
    }
}

template <class T, int Factor>
void test_with_small_exponents()
{
    test_with_big_bases<0, T>();
    test_with_big_bases<Factor*1, T>();
    test_with_big_bases<Factor*2, T>();
    test_with_big_bases<Factor*3, T>();
    test_with_big_bases<Factor*5, T>();
    test_with_big_bases<Factor*6, T>();
    test_with_big_bases<Factor*7, T>();
    test_with_big_bases<Factor*8, T>();
    test_with_big_bases<Factor*9, T>();
    test_with_big_bases<Factor*10, T>();
    test_with_big_bases<Factor*11, T>();
    test_with_big_bases<Factor*12, T>();
}

template <class T, int Factor>
void test_with_big_exponents()
{
    test_with_small_bases<Factor*50, T>();
    test_with_small_bases<Factor*100, T>();
    test_with_small_bases<Factor*150, T>();
    test_with_small_bases<Factor*200, T>();
    test_with_small_bases<Factor*250, T>();
    test_with_small_bases<Factor*300, T>();
    test_with_small_bases<Factor*350, T>();
    test_with_small_bases<Factor*400, T>();
    test_with_small_bases<Factor*450, T>();
    test_with_small_bases<Factor*500, T>();
}


void test_return_types()
{
    BOOST_STATIC_ASSERT((is_same<BOOST_TYPEOF(pow<2>('\1')), double>::value));
    BOOST_STATIC_ASSERT((is_same<BOOST_TYPEOF(pow<2>(L'\2')), double>::value));
    BOOST_STATIC_ASSERT((is_same<BOOST_TYPEOF(pow<2>(3)), double>::value));
    BOOST_STATIC_ASSERT((is_same<BOOST_TYPEOF(pow<2>(4u)), double>::value));
    BOOST_STATIC_ASSERT((is_same<BOOST_TYPEOF(pow<2>(5ul)), double>::value));
    BOOST_STATIC_ASSERT((is_same<BOOST_TYPEOF(pow<2>(6.0f)), float>::value));
    BOOST_STATIC_ASSERT((is_same<BOOST_TYPEOF(pow<2>(7.0)), double>::value));
#ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS
    BOOST_STATIC_ASSERT((is_same<BOOST_TYPEOF(pow<2>(7.0l)), long double>::value));
#endif
}


namespace boost { namespace math { namespace policies {
template <class T>
T user_overflow_error(const char*, const char*, const T&)
{ return T(123.45); }
}}}

namespace boost { namespace math { namespace policies {
template <class T>
T user_indeterminate_result_error(const char*, const char*, const T&)
{ return T(456.78); }
}}}


void test_error_policy()
{
    using namespace policies;

    BOOST_CHECK(pow<-2>(
                    0.0,
                    policy< ::boost::math::policies::overflow_error<user_error> >()
                )
                == 123.45);

    BOOST_CHECK(pow<0>(
                    0.0,
                    policy< ::boost::math::policies::indeterminate_result_error<user_error> >()
                )
                == 456.78);
}

int test_main(int, char* [])
{
    using namespace std;

    cout << "Testing with integral bases and positive small exponents" << endl;
    test_with_small_exponents<int, 1>();
    cout << "Testing with integral bases and negative small exponents" << endl;
    test_with_small_exponents<int, -1>();

    cout << "Testing with float precision bases and positive small exponents" << endl;
    test_with_small_exponents<float, 1>();
    cout << "Testing with float precision bases and negative small exponents" << endl;
    test_with_small_exponents<float, -1>();

    cout << "Testing with float precision bases and positive big exponents" << endl;
    test_with_big_exponents<float, 1>();
    cout << "Testing with float precision bases and negative big exponents" << endl;
    test_with_big_exponents<float, -1>();

     cout << "Testing with double precision bases and positive small exponents" << endl;
    test_with_small_exponents<double, 1>();
    cout << "Testing with double precision bases and negative small exponents" << endl;
    test_with_small_exponents<double, -1>();

    cout << "Testing with double precision bases and positive big exponents" << endl;
    test_with_big_exponents<double, 1>();
    cout << "Testing with double precision bases and negative big exponents" << endl;
    test_with_big_exponents<double, -1>();

#ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS
    cout << "Testing with long double precision bases and positive small exponents" << endl;
    test_with_small_exponents<long double, 1>();
    cout << "Testing with long double precision bases and negative small exponents" << endl;
    test_with_small_exponents<long double, -1>();

    cout << "Testing with long double precision bases and positive big exponents" << endl;
    test_with_big_exponents<long double, 1>();
    cout << "Testing with long double precision bases and negative big exponents" << endl;
    test_with_big_exponents<long double, -1>();

    cout << "Testing with concepts::real_concept precision bases and positive small exponents" << endl;
    test_with_small_exponents<concepts::real_concept, 1>();
    cout << "Testing with concepts::real_concept precision bases and negative small exponents" << endl;
    test_with_small_exponents<concepts::real_concept, -1>();

    cout << "Testing with concepts::real_concept precision bases and positive big exponents" << endl;
    test_with_big_exponents<concepts::real_concept, 1>();
    cout << "Testing with concepts::real_concept precision bases and negative big exponents" << endl;
    test_with_big_exponents<concepts::real_concept, -1>();
#endif

    test_return_types();

    test_error_policy();

    return 0;
}