| // Copyright John Maddock 2007. |
| // Copyright Paul A. Bristow 2007. |
| |
| // 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) |
| |
| #ifndef BOOST_STATS_FIND_LOCATION_HPP |
| #define BOOST_STATS_FIND_LOCATION_HPP |
| |
| #include <boost/math/distributions/fwd.hpp> // for all distribution signatures. |
| #include <boost/math/distributions/complement.hpp> |
| #include <boost/math/policies/policy.hpp> |
| #include <boost/math/tools/traits.hpp> |
| #include <boost/static_assert.hpp> |
| #include <boost/math/special_functions/fpclassify.hpp> |
| #include <boost/math/policies/error_handling.hpp> |
| // using boost::math::policies::policy; |
| // using boost::math::complement; // will be needed by users who want complement, |
| // but NOT placed here to avoid putting it in global scope. |
| |
| namespace boost |
| { |
| namespace math |
| { |
| // Function to find location of random variable z |
| // to give probability p (given scale) |
| // Applies to normal, lognormal, extreme value, Cauchy, (and symmetrical triangular), |
| // enforced by BOOST_STATIC_ASSERT below. |
| |
| template <class Dist, class Policy> |
| inline |
| typename Dist::value_type find_location( // For example, normal mean. |
| typename Dist::value_type z, // location of random variable z to give probability, P(X > z) == p. |
| // For example, a nominal minimum acceptable z, so that p * 100 % are > z |
| typename Dist::value_type p, // probability value desired at x, say 0.95 for 95% > z. |
| typename Dist::value_type scale, // scale parameter, for example, normal standard deviation. |
| const Policy& pol |
| ) |
| { |
| #if !defined(BOOST_NO_SFINAE) && !BOOST_WORKAROUND(__SUNPRO_CC, BOOST_TESTED_AT(0x590)) |
| // Will fail to compile here if try to use with a distribution without scale & location, |
| // for example pareto, and many others. These tests are disabled by the pp-logic |
| // above if the compiler doesn't support the SFINAE tricks used in the traits class. |
| BOOST_STATIC_ASSERT(::boost::math::tools::is_distribution<Dist>::value); |
| BOOST_STATIC_ASSERT(::boost::math::tools::is_scaled_distribution<Dist>::value); |
| #endif |
| static const char* function = "boost::math::find_location<Dist, Policy>&, %1%)"; |
| |
| if(!(boost::math::isfinite)(p) || (p < 0) || (p > 1)) |
| { |
| return policies::raise_domain_error<typename Dist::value_type>( |
| function, "Probability parameter was %1%, but must be >= 0 and <= 1!", p, pol); |
| } |
| if(!(boost::math::isfinite)(z)) |
| { |
| return policies::raise_domain_error<typename Dist::value_type>( |
| function, "z parameter was %1%, but must be finite!", z, pol); |
| } |
| if(!(boost::math::isfinite)(scale)) |
| { |
| return policies::raise_domain_error<typename Dist::value_type>( |
| function, "scale parameter was %1%, but must be finite!", scale, pol); |
| } |
| |
| //cout << "z " << z << ", p " << p << ", quantile(Dist(), p) " |
| // << quantile(Dist(), p) << ", quan * scale " << quantile(Dist(), p) * scale << endl; |
| return z - (quantile(Dist(), p) * scale); |
| } // find_location |
| |
| template <class Dist> |
| inline // with default policy. |
| typename Dist::value_type find_location( // For example, normal mean. |
| typename Dist::value_type z, // location of random variable z to give probability, P(X > z) == p. |
| // For example, a nominal minimum acceptable z, so that p * 100 % are > z |
| typename Dist::value_type p, // probability value desired at x, say 0.95 for 95% > z. |
| typename Dist::value_type scale) // scale parameter, for example, normal standard deviation. |
| { // Forward to find_location with default policy. |
| return (find_location<Dist>(z, p, scale, policies::policy<>())); |
| } // find_location |
| |
| // So the user can start from the complement q = (1 - p) of the probability p, |
| // for example, l = find_location<normal>(complement(z, q, sd)); |
| |
| template <class Dist, class Real1, class Real2, class Real3> |
| inline typename Dist::value_type find_location( // Default policy. |
| complemented3_type<Real1, Real2, Real3> const& c) |
| { |
| static const char* function = "boost::math::find_location<Dist, Policy>&, %1%)"; |
| |
| typename Dist::value_type p = c.param1; |
| if(!(boost::math::isfinite)(p) || (p < 0) || (p > 1)) |
| { |
| return policies::raise_domain_error<typename Dist::value_type>( |
| function, "Probability parameter was %1%, but must be >= 0 and <= 1!", p, policies::policy<>()); |
| } |
| typename Dist::value_type z = c.dist; |
| if(!(boost::math::isfinite)(z)) |
| { |
| return policies::raise_domain_error<typename Dist::value_type>( |
| function, "z parameter was %1%, but must be finite!", z, policies::policy<>()); |
| } |
| typename Dist::value_type scale = c.param2; |
| if(!(boost::math::isfinite)(scale)) |
| { |
| return policies::raise_domain_error<typename Dist::value_type>( |
| function, "scale parameter was %1%, but must be finite!", scale, policies::policy<>()); |
| } |
| // cout << "z " << c.dist << ", quantile (Dist(), " << c.param1 << ") * scale " << c.param2 << endl; |
| return z - quantile(Dist(), p) * scale; |
| } // find_location complement |
| |
| |
| template <class Dist, class Real1, class Real2, class Real3, class Real4> |
| inline typename Dist::value_type find_location( // Explicit policy. |
| complemented4_type<Real1, Real2, Real3, Real4> const& c) |
| { |
| static const char* function = "boost::math::find_location<Dist, Policy>&, %1%)"; |
| |
| typename Dist::value_type p = c.param1; |
| if(!(boost::math::isfinite)(p) || (p < 0) || (p > 1)) |
| { |
| return policies::raise_domain_error<typename Dist::value_type>( |
| function, "Probability parameter was %1%, but must be >= 0 and <= 1!", p, c.param3); |
| } |
| typename Dist::value_type z = c.dist; |
| if(!(boost::math::isfinite)(z)) |
| { |
| return policies::raise_domain_error<typename Dist::value_type>( |
| function, "z parameter was %1%, but must be finite!", z, c.param3); |
| } |
| typename Dist::value_type scale = c.param2; |
| if(!(boost::math::isfinite)(scale)) |
| { |
| return policies::raise_domain_error<typename Dist::value_type>( |
| function, "scale parameter was %1%, but must be finite!", scale, c.param3); |
| } |
| // cout << "z " << c.dist << ", quantile (Dist(), " << c.param1 << ") * scale " << c.param2 << endl; |
| return z - quantile(Dist(), p) * scale; |
| } // find_location complement |
| |
| } // namespace boost |
| } // namespace math |
| |
| #endif // BOOST_STATS_FIND_LOCATION_HPP |
| |