epoc32/include/stdapis/boost/math/complex/atanh.hpp
branchSymbian2
changeset 3 e1b950c65cb4
parent 2 2fe1408b6811
child 4 837f303aceeb
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/epoc32/include/stdapis/boost/math/complex/atanh.hpp	Wed Mar 31 12:27:01 2010 +0100
@@ -0,0 +1,267 @@
+//    boost atanh.hpp header file
+
+//  (C) Copyright Hubert Holin 2001.
+//  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)
+
+// See http://www.boost.org for updates, documentation, and revision history.
+
+#ifndef BOOST_ATANH_HPP
+#define BOOST_ATANH_HPP
+
+
+#include <cmath>
+#include <limits>
+#include <string>
+#include <stdexcept>
+
+
+#include <boost/config.hpp>
+
+
+// This is the inverse of the hyperbolic tangent function.
+
+namespace boost
+{
+    namespace math
+    {
+#if defined(__GNUC__) && (__GNUC__ < 3)
+        // gcc 2.x ignores function scope using declarations,
+        // put them in the scope of the enclosing namespace instead:
+        
+        using    ::std::abs;
+        using    ::std::sqrt;
+        using    ::std::log;
+        
+        using    ::std::numeric_limits;
+#endif
+        
+#if defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION)
+        // This is the main fare
+        
+        template<typename T>
+        inline T    atanh(const T x)
+        {
+            using    ::std::abs;
+            using    ::std::sqrt;
+            using    ::std::log;
+            
+            using    ::std::numeric_limits;
+            
+            T const            one = static_cast<T>(1);
+            T const            two = static_cast<T>(2);
+            
+            static T const    taylor_2_bound = sqrt(numeric_limits<T>::epsilon());
+            static T const    taylor_n_bound = sqrt(taylor_2_bound);
+            
+            if        (x < -one)
+            {
+                if    (numeric_limits<T>::has_quiet_NaN)
+                {
+                    return(numeric_limits<T>::quiet_NaN());
+                }
+                else
+                {
+                    ::std::string        error_reporting("Argument to atanh is strictly greater than +1 or strictly smaller than -1!");
+                    ::std::domain_error  bad_argument(error_reporting);
+                    
+                    throw(bad_argument);
+                }
+            }
+            else if    (x < -one+numeric_limits<T>::epsilon())
+            {
+                if    (numeric_limits<T>::has_infinity)
+                {
+                    return(-numeric_limits<T>::infinity());
+                }
+                else
+                {
+                    ::std::string        error_reporting("Argument to atanh is -1 (result: -Infinity)!");
+                    ::std::out_of_range  bad_argument(error_reporting);
+                    
+                    throw(bad_argument);
+                }
+            }
+            else if    (x > +one-numeric_limits<T>::epsilon())
+            {
+                if    (numeric_limits<T>::has_infinity)
+                {
+                    return(+numeric_limits<T>::infinity());
+                }
+                else
+                {
+                    ::std::string        error_reporting("Argument to atanh is +1 (result: +Infinity)!");
+                    ::std::out_of_range  bad_argument(error_reporting);
+                    
+                    throw(bad_argument);
+                }
+            }
+            else if    (x > +one)
+            {
+                if    (numeric_limits<T>::has_quiet_NaN)
+                {
+                    return(numeric_limits<T>::quiet_NaN());
+                }
+                else
+                {
+                    ::std::string        error_reporting("Argument to atanh is strictly greater than +1 or strictly smaller than -1!");
+                    ::std::domain_error  bad_argument(error_reporting);
+                    
+                    throw(bad_argument);
+                }
+            }
+            else if    (abs(x) >= taylor_n_bound)
+            {
+                return(log( (one + x) / (one - x) ) / two);
+            }
+            else
+            {
+                // approximation by taylor series in x at 0 up to order 2
+                T    result = x;
+                
+                if    (abs(x) >= taylor_2_bound)
+                {
+                    T    x3 = x*x*x;
+                    
+                    // approximation by taylor series in x at 0 up to order 4
+                    result += x3/static_cast<T>(3);
+                }
+                
+                return(result);
+            }
+        }
+#else
+        // These are implementation details (for main fare see below)
+        
+        namespace detail
+        {
+            template    <
+                            typename T,
+                            bool InfinitySupported
+                        >
+            struct    atanh_helper1_t
+            {
+                static T    get_pos_infinity()
+                {
+                    return(+::std::numeric_limits<T>::infinity());
+                }
+                
+                static T    get_neg_infinity()
+                {
+                    return(-::std::numeric_limits<T>::infinity());
+                }
+            };    // boost::math::detail::atanh_helper1_t
+            
+            
+            template<typename T>
+            struct    atanh_helper1_t<T, false>
+            {
+                static T    get_pos_infinity()
+                {
+                    ::std::string        error_reporting("Argument to atanh is +1 (result: +Infinity)!");
+                    ::std::out_of_range  bad_argument(error_reporting);
+                    
+                    throw(bad_argument);
+                }
+                
+                static T    get_neg_infinity()
+                {
+                    ::std::string        error_reporting("Argument to atanh is -1 (result: -Infinity)!");
+                    ::std::out_of_range  bad_argument(error_reporting);
+                    
+                    throw(bad_argument);
+                }
+            };    // boost::math::detail::atanh_helper1_t
+            
+            
+            template    <
+                            typename T,
+                            bool QuietNanSupported
+                        >
+            struct    atanh_helper2_t
+            {
+                static T    get_NaN()
+                {
+                    return(::std::numeric_limits<T>::quiet_NaN());
+                }
+            };    // boost::detail::atanh_helper2_t
+            
+            
+            template<typename T>
+            struct    atanh_helper2_t<T, false>
+            {
+                static T    get_NaN()
+                {
+                    ::std::string        error_reporting("Argument to atanh is strictly greater than +1 or strictly smaller than -1!");
+                    ::std::domain_error  bad_argument(error_reporting);
+                    
+                    throw(bad_argument);
+                }
+            };    // boost::detail::atanh_helper2_t
+        }    // boost::detail
+        
+        
+        // This is the main fare
+        
+        template<typename T>
+        inline T    atanh(const T x)
+        {
+            using    ::std::abs;
+            using    ::std::sqrt;
+            using    ::std::log;
+            
+            using    ::std::numeric_limits;
+            
+            typedef  detail::atanh_helper1_t<T, ::std::numeric_limits<T>::has_infinity>    helper1_type;
+            typedef  detail::atanh_helper2_t<T, ::std::numeric_limits<T>::has_quiet_NaN>    helper2_type;
+            
+            
+            T const           one = static_cast<T>(1);
+            T const           two = static_cast<T>(2);
+            
+            static T const    taylor_2_bound = sqrt(numeric_limits<T>::epsilon());
+            static T const    taylor_n_bound = sqrt(taylor_2_bound);
+            
+            if        (x < -one)
+            {
+                return(helper2_type::get_NaN());
+            }
+            else if    (x < -one+numeric_limits<T>::epsilon())
+            {
+                return(helper1_type::get_neg_infinity());
+            }
+            else if    (x > +one-numeric_limits<T>::epsilon())
+            {
+                return(helper1_type::get_pos_infinity());
+            }
+            else if    (x > +one)
+            {
+                return(helper2_type::get_NaN());
+            }
+            else if    (abs(x) >= taylor_n_bound)
+            {
+                return(log( (one + x) / (one - x) ) / two);
+            }
+            else
+            {
+                // approximation by taylor series in x at 0 up to order 2
+                T    result = x;
+                
+                if    (abs(x) >= taylor_2_bound)
+                {
+                    T    x3 = x*x*x;
+                    
+                    // approximation by taylor series in x at 0 up to order 4
+                    result += x3/static_cast<T>(3);
+                }
+                
+                return(result);
+            }
+        }
+#endif /* defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) */
+    }
+}
+
+#endif /* BOOST_ATANH_HPP */
+