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			916 lines
		
	
	
		
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			916 lines
		
	
	
		
			34 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
|  | // Copyright Paul A. Bristow 2015
 | ||
|  | 
 | ||
|  | // 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)
 | ||
|  | 
 | ||
|  | // Comparison of finding roots using TOMS748, Newton-Raphson, Schroder & Halley algorithms.
 | ||
|  | 
 | ||
|  | // Note that this file contains Quickbook mark-up as well as code
 | ||
|  | // and comments, don't change any of the special comment mark-ups!
 | ||
|  | 
 | ||
|  | // root_finding_algorithms.cpp
 | ||
|  | 
 | ||
|  | #include <boost/cstdlib.hpp>
 | ||
|  | #include <boost/config.hpp>
 | ||
|  | #include <boost/array.hpp>
 | ||
|  | #include <boost/type_traits/is_floating_point.hpp>
 | ||
|  | 
 | ||
|  | #include "table_type.hpp"
 | ||
|  | // Copy of i:\modular-boost\libs\math\test\table_type.hpp
 | ||
|  | // #include "handle_test_result.hpp"
 | ||
|  | // Copy of i:\modular - boost\libs\math\test\handle_test_result.hpp
 | ||
|  | 
 | ||
|  | #include <boost/math/tools/roots.hpp>
 | ||
|  | //using boost::math::policies::policy;
 | ||
|  | //using boost::math::tools::newton_raphson_iterate;
 | ||
|  | //using boost::math::tools::halley_iterate; //
 | ||
|  | //using boost::math::tools::eps_tolerance; // Binary functor for specified number of bits.
 | ||
|  | //using boost::math::tools::bracket_and_solve_root;
 | ||
|  | //using boost::math::tools::toms748_solve;
 | ||
|  | //using boost::math::tools::schroder_iterate;
 | ||
|  | 
 | ||
|  | #include <boost/math/special_functions/next.hpp> // For float_distance.
 | ||
|  | #include <tuple> // for tuple and make_tuple.
 | ||
|  | #include <boost/math/special_functions/cbrt.hpp> // For boost::math::cbrt.
 | ||
|  | 
 | ||
|  | #include <boost/multiprecision/cpp_bin_float.hpp> // is binary.
 | ||
|  | //#include <boost/multiprecision/cpp_dec_float.hpp> // is decimal.
 | ||
|  | using boost::multiprecision::cpp_bin_float_100; | ||
|  | using boost::multiprecision::cpp_bin_float_50; | ||
|  | 
 | ||
|  | #include <boost/timer/timer.hpp>
 | ||
|  | #include <boost/system/error_code.hpp>
 | ||
|  | #include <boost/multiprecision/cpp_bin_float/io.hpp>
 | ||
|  | #include <boost/preprocessor/stringize.hpp>
 | ||
|  | 
 | ||
|  | // STL
 | ||
|  | #include <iostream>
 | ||
|  | #include <iomanip>
 | ||
|  | #include <string>
 | ||
|  | #include <vector>
 | ||
|  | #include <limits>
 | ||
|  | #include <fstream> // std::ofstream
 | ||
|  | #include <cmath>
 | ||
|  | #include <typeinfo> // for type name using typid(thingy).name();
 | ||
|  | 
 | ||
|  | #ifndef BOOST_ROOT
 | ||
|  | # define BOOST_ROOT i:/modular-boost/
 | ||
|  | #endif
 | ||
|  | // Need to find this 
 | ||
|  | 
 | ||
|  | #ifdef __FILE__
 | ||
|  | std::string sourcefilename = __FILE__; | ||
|  | #endif
 | ||
|  | 
 | ||
|  | std::string chop_last(std::string s) | ||
|  | { | ||
|  |    std::string::size_type pos = s.find_last_of("\\/"); | ||
|  |    if(pos != std::string::npos) | ||
|  |       s.erase(pos); | ||
|  |    else if(s.empty()) | ||
|  |       abort(); | ||
|  |    else | ||
|  |       s.erase(); | ||
|  |    return s; | ||
|  | } | ||
|  | 
 | ||
|  | std::string make_root() | ||
|  | { | ||
|  |    std::string result; | ||
|  |    if(sourcefilename.find_first_of(":") != std::string::npos) | ||
|  |    { | ||
|  |       result = chop_last(sourcefilename); // lose filename part
 | ||
|  |       result = chop_last(result);   // lose /example/
 | ||
|  |       result = chop_last(result);   // lose /math/
 | ||
|  |       result = chop_last(result);   // lose /libs/
 | ||
|  |    } | ||
|  |    else | ||
|  |    { | ||
|  |       result = chop_last(sourcefilename); // lose filename part
 | ||
|  |       if(result.empty()) | ||
|  |          result = "."; | ||
|  |       result += "/../../.."; | ||
|  |    } | ||
|  |    return result; | ||
|  | } | ||
|  | 
 | ||
|  | std::string short_file_name(std::string s) | ||
|  | { | ||
|  |    std::string::size_type pos = s.find_last_of("\\/"); | ||
|  |    if(pos != std::string::npos) | ||
|  |       s.erase(0, pos + 1); | ||
|  |    return s; | ||
|  | } | ||
|  | 
 | ||
|  | std::string boost_root = make_root(); | ||
|  | 
 | ||
|  | #ifdef _MSC_VER
 | ||
|  |   std::string filename = boost_root.append("/libs/math/doc/roots/root_comparison_tables_msvc.qbk"); | ||
|  | #else // assume GCC
 | ||
|  |   std::string filename = boost_root.append("/libs/math/doc/roots/root_comparison_tables_gcc.qbk"); | ||
|  | #endif
 | ||
|  | 
 | ||
|  | std::ofstream fout (filename.c_str(), std::ios_base::out); | ||
|  | 
 | ||
|  | //std::array<std::string, 6> float_type_names =
 | ||
|  | //{
 | ||
|  | //  "float", "double", "long double", "cpp_bin_128", "cpp_dec_50", "cpp_dec_100"
 | ||
|  | //};
 | ||
|  | 
 | ||
|  | std::vector<std::string> algo_names = | ||
|  | { | ||
|  |   "cbrt", "TOMS748", "Newton", "Halley", "Schr'''ö'''der" | ||
|  | }; | ||
|  | 
 | ||
|  | std::vector<int> max_digits10s; | ||
|  | std::vector<std::string> typenames; // Full computer generated type name.
 | ||
|  | std::vector<std::string> names; // short name.
 | ||
|  | 
 | ||
|  | uintmax_t iters; // Global as iterations is not returned by rooting function.
 | ||
|  | 
 | ||
|  | const int convert = 1000; // convert nanoseconds to microseconds (assuming this is resolution).
 | ||
|  | 
 | ||
|  | const int count = 1000000; // Number of iterations to average.
 | ||
|  |   | ||
|  | struct root_info | ||
|  | { // for a floating-point type, float, double ...
 | ||
|  |   std::size_t max_digits10; // for type.
 | ||
|  |   std::string full_typename; // for type from type_id.name().
 | ||
|  |   std::string short_typename; // for type "float", "double", "cpp_bin_float_50" ....
 | ||
|  | 
 | ||
|  |   std::size_t bin_digits;  // binary in floating-point type numeric_limits<T>::digits;  
 | ||
|  |   int get_digits; // fraction of maximum possible accuracy required.
 | ||
|  |   // = digits * digits_accuracy
 | ||
|  |   // Vector of values for each algorithm, std::cbrt, boost::math::cbrt, TOMS748, Newton, Halley.
 | ||
|  |   //std::vector< boost::int_least64_t> times;  converted to int.
 | ||
|  |   std::vector<int> times; | ||
|  |   //boost::int_least64_t min_time = std::numeric_limits<boost::int_least64_t>::max(); // Used to normalize times (as int).
 | ||
|  |   std::vector<double> normed_times; | ||
|  |   boost::int_least64_t min_time = (std::numeric_limits<boost::int_least64_t>::max)(); // Used to normalize times.
 | ||
|  |   std::vector<uintmax_t> iterations; | ||
|  |   std::vector<long int> distances; | ||
|  |   std::vector<cpp_bin_float_100> full_results; | ||
|  | }; // struct root_info
 | ||
|  | 
 | ||
|  | std::vector<root_info> root_infos;  // One element for each type used.
 | ||
|  | 
 | ||
|  | int type_no = -1; // float = 0, double = 1, ... indexing root_infos.
 | ||
|  | 
 | ||
|  | inline std::string build_test_name(const char* type_name, const char* test_name) | ||
|  | { | ||
|  |   std::string result(BOOST_COMPILER); | ||
|  |   result += "|"; | ||
|  |   result += BOOST_STDLIB; | ||
|  |   result += "|"; | ||
|  |   result += BOOST_PLATFORM; | ||
|  |   result += "|"; | ||
|  |   result += type_name; | ||
|  |   result += "|"; | ||
|  |   result += test_name; | ||
|  | #if defined(_DEBUG ) || !defined(NDEBUG)
 | ||
|  |   result += "|"; | ||
|  |   result += " debug"; | ||
|  | #else
 | ||
|  |   result += "|"; | ||
|  |   result += " release"; | ||
|  | #endif
 | ||
|  |   result += "|"; | ||
|  |     return result; | ||
|  | } | ||
|  | 
 | ||
|  | // No derivatives - using TOMS748 internally.
 | ||
|  | template <class T> | ||
|  | struct cbrt_functor_noderiv | ||
|  | { //  cube root of x using only function - no derivatives.
 | ||
|  |   cbrt_functor_noderiv(T const& to_find_root_of) : a(to_find_root_of) | ||
|  |   { // Constructor just stores value a to find root of.
 | ||
|  |   } | ||
|  |   T operator()(T const& x) | ||
|  |   { | ||
|  |     T fx = x*x*x - a; // Difference (estimate x^3 - a).
 | ||
|  |     return fx; | ||
|  |   } | ||
|  | private: | ||
|  |   T a; // to be 'cube_rooted'.
 | ||
|  | }; // template <class T> struct cbrt_functor_noderiv
 | ||
|  | 
 | ||
|  | template <class T> | ||
|  | T cbrt_noderiv(T x) | ||
|  | { // return cube root of x using bracket_and_solve (using NO derivatives).
 | ||
|  |   using namespace std;  // Help ADL of std functions.
 | ||
|  |   using namespace boost::math::tools; // For bracket_and_solve_root.
 | ||
|  | 
 | ||
|  |   // Maybe guess should be double, or use enable_if to avoid warning about conversion double to float here?
 | ||
|  |   T guess; | ||
|  |   if (boost::is_fundamental<T>::value) | ||
|  |   {  | ||
|  |     int exponent; | ||
|  |     frexp(x, &exponent); // Get exponent of z (ignore mantissa).
 | ||
|  |     guess = ldexp((T)1., exponent / 3); // Rough guess is to divide the exponent by three.
 | ||
|  |   } | ||
|  |   else | ||
|  |   { // (boost::is_class<T>)
 | ||
|  |     double dx = static_cast<double>(x); | ||
|  |     guess = boost::math::cbrt<T>(dx); // Get guess using double.
 | ||
|  |   } | ||
|  |    | ||
|  |   T factor = 2; // How big steps to take when searching.
 | ||
|  | 
 | ||
|  |   const boost::uintmax_t maxit = 50; // Limit to maximum iterations.
 | ||
|  |   boost::uintmax_t it = maxit; // Initally our chosen max iterations, but updated with actual.
 | ||
|  |   bool is_rising = true; // So if result if guess^3 is too low, then try increasing guess.
 | ||
|  |   int digits = std::numeric_limits<T>::digits; // Maximum possible binary digits accuracy for type T.
 | ||
|  |   // Some fraction of digits is used to control how accurate to try to make the result.
 | ||
|  |   int get_digits = static_cast<int>(std::numeric_limits<T>::digits - 2); | ||
|  | 
 | ||
|  |   eps_tolerance<T> tol(get_digits); // Set the tolerance.
 | ||
|  |   std::pair<T, T> r = | ||
|  |     bracket_and_solve_root(cbrt_functor_noderiv<T>(x), guess, factor, is_rising, tol, it); | ||
|  |   iters = it; | ||
|  |   T result = r.first + (r.second - r.first) / 2;  // Midway between brackets.
 | ||
|  |   return result; | ||
|  | } // template <class T> T cbrt_noderiv(T x)
 | ||
|  | 
 | ||
|  | 
 | ||
|  | // Using 1st derivative only Newton-Raphson
 | ||
|  | 
 | ||
|  | template <class T> | ||
|  | struct cbrt_functor_deriv | ||
|  | { // Functor also returning 1st derviative.
 | ||
|  |   cbrt_functor_deriv(T const& to_find_root_of) : a(to_find_root_of) | ||
|  |   { // Constructor stores value a to find root of,
 | ||
|  |     // for example: calling cbrt_functor_deriv<T>(x) to use to get cube root of x.
 | ||
|  |   } | ||
|  |   std::pair<T, T> operator()(T const& x) | ||
|  |   { // Return both f(x) and f'(x).
 | ||
|  |     T fx = x*x*x - a; // Difference (estimate x^3 - value).
 | ||
|  |     T dx = 3 * x*x; // 1st derivative = 3x^2.
 | ||
|  |     return std::make_pair(fx, dx); // 'return' both fx and dx.
 | ||
|  |   } | ||
|  | private: | ||
|  |   T a; // to be 'cube_rooted'.
 | ||
|  | }; | ||
|  | 
 | ||
|  | template <class T> | ||
|  | T cbrt_deriv(T x) | ||
|  | { // return cube root of x using 1st derivative and Newton_Raphson.
 | ||
|  |   using namespace boost::math::tools; | ||
|  |   int exponent; | ||
|  |   T guess; | ||
|  |   if(boost::is_fundamental<T>::value) | ||
|  |   { | ||
|  |      frexp(x, &exponent); // Get exponent of z (ignore mantissa).
 | ||
|  |      guess = ldexp(static_cast<T>(1), exponent / 3); // Rough guess is to divide the exponent by three.
 | ||
|  |   } | ||
|  |   else | ||
|  |      guess = boost::math::cbrt(static_cast<double>(x)); | ||
|  |   T min = guess / 2; // Minimum possible value is half our guess.
 | ||
|  |   T max = 2 * guess; // Maximum possible value is twice our guess.
 | ||
|  |   const int digits = std::numeric_limits<T>::digits; // Maximum possible binary digits accuracy for type T.
 | ||
|  |   int get_digits = static_cast<int>(std::numeric_limits<T>::digits * 0.6); | ||
|  |   const boost::uintmax_t maxit = 20; | ||
|  |   boost::uintmax_t it = maxit; | ||
|  |   T result = newton_raphson_iterate(cbrt_functor_deriv<T>(x), guess, min, max, get_digits, it); | ||
|  |   iters = it; | ||
|  |   return result; | ||
|  | } | ||
|  | 
 | ||
|  | // Using 1st and 2nd derivatives with Halley algorithm.
 | ||
|  | 
 | ||
|  | template <class T> | ||
|  | struct cbrt_functor_2deriv | ||
|  | { // Functor returning both 1st and 2nd derivatives.
 | ||
|  |   cbrt_functor_2deriv(T const& to_find_root_of) : a(to_find_root_of) | ||
|  |   { // Constructor stores value a to find root of, for example:
 | ||
|  |     // calling cbrt_functor_2deriv<T>(x) to get cube root of x,
 | ||
|  |   } | ||
|  |   std::tuple<T, T, T> operator()(T const& x) | ||
|  |   { // Return both f(x) and f'(x) and f''(x).
 | ||
|  |     T fx = x*x*x - a; // Difference (estimate x^3 - value).
 | ||
|  |     T dx = 3 * x*x; // 1st derivative = 3x^2.
 | ||
|  |     T d2x = 6 * x; // 2nd derivative = 6x.
 | ||
|  |     return std::make_tuple(fx, dx, d2x); // 'return' fx, dx and d2x.
 | ||
|  |   } | ||
|  | private: | ||
|  |   T a; // to be 'cube_rooted'.
 | ||
|  | }; | ||
|  | 
 | ||
|  | template <class T> | ||
|  | T cbrt_2deriv(T x) | ||
|  | { // return cube root of x using 1st and 2nd derivatives and Halley.
 | ||
|  |   //using namespace std;  // Help ADL of std functions.
 | ||
|  |   using namespace boost::math::tools; | ||
|  |   int exponent; | ||
|  |   T guess; | ||
|  |   if(boost::is_fundamental<T>::value) | ||
|  |   { | ||
|  |      frexp(x, &exponent); // Get exponent of z (ignore mantissa).
 | ||
|  |      guess = ldexp(static_cast<T>(1), exponent / 3); // Rough guess is to divide the exponent by three.
 | ||
|  |   } | ||
|  |   else | ||
|  |      guess = boost::math::cbrt(static_cast<double>(x)); | ||
|  |   T min = guess / 2; // Minimum possible value is half our guess.
 | ||
|  |   T max = 2 * guess; // Maximum possible value is twice our guess.
 | ||
|  |   const int digits = std::numeric_limits<T>::digits; // Maximum possible binary digits accuracy for type T.
 | ||
|  |   // digits used to control how accurate to try to make the result.
 | ||
|  |   int get_digits = static_cast<int>(std::numeric_limits<T>::digits * 0.4); | ||
|  |   boost::uintmax_t maxit = 20; | ||
|  |   boost::uintmax_t it = maxit; | ||
|  |   T result = halley_iterate(cbrt_functor_2deriv<T>(x), guess, min, max, get_digits, it); | ||
|  |   iters = it; | ||
|  |   return result; | ||
|  | } | ||
|  | 
 | ||
|  | // Using 1st and 2nd derivatives using Schroder algorithm.
 | ||
|  | 
 | ||
|  | template <class T> | ||
|  | T cbrt_2deriv_s(T x) | ||
|  | { // return cube root of x using 1st and 2nd derivatives and Schroder algorithm.
 | ||
|  |   //using namespace std;  // Help ADL of std functions.
 | ||
|  |   using namespace boost::math::tools; | ||
|  |   int exponent; | ||
|  |   T guess; | ||
|  |   if(boost::is_fundamental<T>::value) | ||
|  |   { | ||
|  |      frexp(x, &exponent); // Get exponent of z (ignore mantissa).
 | ||
|  |      guess = ldexp(static_cast<T>(1), exponent / 3); // Rough guess is to divide the exponent by three.
 | ||
|  |   } | ||
|  |   else | ||
|  |      guess = boost::math::cbrt(static_cast<double>(x)); | ||
|  |   T min = guess / 2; // Minimum possible value is half our guess.
 | ||
|  |   T max = 2 * guess; // Maximum possible value is twice our guess.
 | ||
|  |   const int digits = std::numeric_limits<T>::digits; // Maximum possible binary digits accuracy for type T.
 | ||
|  |   // digits used to control how accurate to try to make the result.
 | ||
|  |   int get_digits = static_cast<int>(std::numeric_limits<T>::digits * 0.4); | ||
|  |   const boost::uintmax_t maxit = 20; | ||
|  |   boost::uintmax_t it = maxit; | ||
|  |   T result = schroder_iterate(cbrt_functor_2deriv<T>(x), guess, min, max, get_digits, it); | ||
|  |   iters = it; | ||
|  |   return result; | ||
|  | } // template <class T> T cbrt_2deriv_s(T x)
 | ||
|  | 
 | ||
|  | 
 | ||
|  | 
 | ||
|  | template <typename T> | ||
|  | int test_root(cpp_bin_float_100 big_value, cpp_bin_float_100 answer, const char* type_name) | ||
|  | { | ||
|  |   //T value = 28.; // integer (exactly representable as floating-point)
 | ||
|  |   // whose cube root is *not* exactly representable.
 | ||
|  |   // Wolfram Alpha command N[28 ^ (1 / 3), 100] computes cube root to 100 decimal digits.
 | ||
|  |   // 3.036588971875662519420809578505669635581453977248111123242141654169177268411884961770250390838097895
 | ||
|  |    | ||
|  |   std::size_t max_digits = 2 + std::numeric_limits<T>::digits * 3010 / 10000; | ||
|  |   // For new versions use max_digits10
 | ||
|  |   // std::cout.precision(std::numeric_limits<T>::max_digits10);
 | ||
|  |   std::cout.precision(max_digits); | ||
|  |   std::cout << std::showpoint << std::endl; // Trailing zeros too.
 | ||
|  | 
 | ||
|  |   root_infos.push_back(root_info()); | ||
|  |   type_no++;  // Another type.
 | ||
|  | 
 | ||
|  |   root_infos[type_no].max_digits10 = max_digits; | ||
|  |   root_infos[type_no].full_typename = typeid(T).name(); // Full typename.
 | ||
|  |   root_infos[type_no].short_typename = type_name; // Short typename.
 | ||
|  | 
 | ||
|  |   root_infos[type_no].bin_digits = std::numeric_limits<T>::digits; | ||
|  | 
 | ||
|  |   root_infos[type_no].get_digits = std::numeric_limits<T>::digits; | ||
|  | 
 | ||
|  |   T to_root = static_cast<T>(big_value); | ||
|  |   T result; // root
 | ||
|  |   T ans = static_cast<T>(answer); | ||
|  |   int algo = 0; // Count of algorithms used.
 | ||
|  |   | ||
|  |   using boost::timer::nanosecond_type; | ||
|  |   using boost::timer::cpu_times; | ||
|  |   using boost::timer::cpu_timer; | ||
|  | 
 | ||
|  |   cpu_times now; // Holds wall, user and system times.
 | ||
|  |   T sum = 0; | ||
|  | 
 | ||
|  |   // std::cbrt is much the fastest, but not useful for this comparison because it only handles fundamental types.
 | ||
|  |   // Using enable_if allows us to avoid a compile fail with multiprecision types, but still distorts the results too much.
 | ||
|  | 
 | ||
|  |   //{
 | ||
|  |   //  algorithm_names.push_back("std::cbrt"); 
 | ||
|  |   //  cpu_timer ti; // Can start, pause, resume and stop, and read elapsed.
 | ||
|  |   //  ti.start();
 | ||
|  |   //  for (long i = 0; i < count; ++i)
 | ||
|  |   //  {
 | ||
|  |   //    stdcbrt(big_value);
 | ||
|  |   //  }
 | ||
|  |   //  now = ti.elapsed();
 | ||
|  |   //  int time = static_cast<int>(now.user / count);
 | ||
|  |   //  root_infos[type_no].times.push_back(time); // CPU time taken per root.
 | ||
|  |   //  if (time < root_infos[type_no].min_time)
 | ||
|  |   //  {
 | ||
|  |   //    root_infos[type_no].min_time = time;
 | ||
|  |   //  }
 | ||
|  |   //  ti.stop();
 | ||
|  |   //  long int distance = static_cast<int>(boost::math::float_distance<T>(result, ans));
 | ||
|  |   //  root_infos[type_no].distances.push_back(distance);
 | ||
|  |   //  root_infos[type_no].iterations.push_back(0); // Not known.
 | ||
|  |   //  root_infos[type_no].full_results.push_back(result);
 | ||
|  |   //  algo++;
 | ||
|  |   //}
 | ||
|  |   //{
 | ||
|  |   //  //algorithm_names.push_back("boost::math::cbrt"); // .
 | ||
|  |   //  cpu_timer ti; // Can start, pause, resume and stop, and read elapsed.
 | ||
|  |   //  ti.start();
 | ||
|  |   //  for (long i = 0; i < count; ++i)
 | ||
|  |   //  {
 | ||
|  |   //    result = boost::math::cbrt(to_root); // 
 | ||
|  |   //  }
 | ||
|  |   //  now = ti.elapsed();
 | ||
|  |   //  int time = static_cast<int>(now.user / count);
 | ||
|  |   //  root_infos[type_no].times.push_back(time); // CPU time taken.
 | ||
|  |   //  ti.stop();
 | ||
|  |   //  if (time < root_infos[type_no].min_time)
 | ||
|  |   //  {
 | ||
|  |   //    root_infos[type_no].min_time = time;
 | ||
|  |   //  }
 | ||
|  |   //  long int distance = static_cast<int>(boost::math::float_distance<T>(result, ans));
 | ||
|  |   //  root_infos[type_no].distances.push_back(distance);
 | ||
|  |   //  root_infos[type_no].iterations.push_back(0); // Iterations not knowable.
 | ||
|  |   //  root_infos[type_no].full_results.push_back(result);
 | ||
|  |   //}
 | ||
|  | 
 | ||
|  | 
 | ||
|  | 
 | ||
|  |   { | ||
|  |     //algorithm_names.push_back("boost::math::cbrt"); // .
 | ||
|  |     result = 0; | ||
|  |     cpu_timer ti; // Can start, pause, resume and stop, and read elapsed.
 | ||
|  |     ti.start(); | ||
|  |     for (long i = 0; i < count; ++i) | ||
|  |     { | ||
|  |       result = boost::math::cbrt(to_root); // 
 | ||
|  |       sum += result; | ||
|  |     } | ||
|  |     now = ti.elapsed(); | ||
|  |     boost:int_least64_t n = now.user; | ||
|  | 
 | ||
|  |     long time = static_cast<long>(now.user/1000); // convert nanoseconds to microseconds (assuming this is resolution).
 | ||
|  |     root_infos[type_no].times.push_back(time); // CPU time taken.
 | ||
|  |     ti.stop(); | ||
|  |     if (time < root_infos[type_no].min_time) | ||
|  |     { | ||
|  |       root_infos[type_no].min_time = time; | ||
|  |     } | ||
|  |     long int distance = static_cast<int>(boost::math::float_distance<T>(result, ans)); | ||
|  |     root_infos[type_no].distances.push_back(distance); | ||
|  |     root_infos[type_no].iterations.push_back(0); // Iterations not knowable.
 | ||
|  |     root_infos[type_no].full_results.push_back(result); | ||
|  |   } | ||
|  |   { | ||
|  |     //algorithm_names.push_back("TOMS748"); // 
 | ||
|  |     cpu_timer ti; // Can start, pause, resume and stop, and read elapsed.
 | ||
|  |     ti.start(); | ||
|  |     for (long i = 0; i < count; ++i) | ||
|  |     { | ||
|  |       result = cbrt_noderiv<T>(to_root); // 
 | ||
|  |       sum += result; | ||
|  |     } | ||
|  |     now = ti.elapsed(); | ||
|  | //    int time = static_cast<int>(now.user / count);
 | ||
|  |     long time = static_cast<long>(now.user/1000); | ||
|  |     root_infos[type_no].times.push_back(time); // CPU time taken.
 | ||
|  |     if (time < root_infos[type_no].min_time) | ||
|  |     { | ||
|  |       root_infos[type_no].min_time = time; | ||
|  |     } | ||
|  |     ti.stop(); | ||
|  |     long int distance = static_cast<int>(boost::math::float_distance<T>(result, ans)); | ||
|  |     root_infos[type_no].distances.push_back(distance); | ||
|  |     root_infos[type_no].iterations.push_back(iters); // 
 | ||
|  |     root_infos[type_no].full_results.push_back(result); | ||
|  |   } | ||
|  |   { | ||
|  |    // algorithm_names.push_back("Newton"); // algorithm
 | ||
|  |     cpu_timer ti; // Can start, pause, resume and stop, and read elapsed.
 | ||
|  |     ti.start(); | ||
|  |     for (long i = 0; i < count; ++i) | ||
|  |     { | ||
|  |       result = cbrt_deriv(to_root); // 
 | ||
|  |       sum += result; | ||
|  |     } | ||
|  |     now = ti.elapsed(); | ||
|  | //    int time = static_cast<int>(now.user / count);
 | ||
|  |     long time = static_cast<long>(now.user/1000); | ||
|  |     root_infos[type_no].times.push_back(time); // CPU time taken.
 | ||
|  |     if (time < root_infos[type_no].min_time) | ||
|  |     { | ||
|  |       root_infos[type_no].min_time = time; | ||
|  |     } | ||
|  | 
 | ||
|  |     ti.stop(); | ||
|  |     long int distance = static_cast<int>(boost::math::float_distance<T>(result, ans)); | ||
|  |     root_infos[type_no].distances.push_back(distance); | ||
|  |     root_infos[type_no].iterations.push_back(iters); //
 | ||
|  |     root_infos[type_no].full_results.push_back(result); | ||
|  |   } | ||
|  |   { | ||
|  |   //algorithm_names.push_back("Halley"); // algorithm
 | ||
|  |     cpu_timer ti; // Can start, pause, resume and stop, and read elapsed.
 | ||
|  |     ti.start(); | ||
|  |     for (long i = 0; i < count; ++i) | ||
|  |     { | ||
|  |       result = cbrt_2deriv(to_root); // 
 | ||
|  |       sum += result; | ||
|  |     } | ||
|  |     now = ti.elapsed();  | ||
|  | //    int time = static_cast<int>(now.user / count);
 | ||
|  |     long time = static_cast<long>(now.user/1000); | ||
|  |     root_infos[type_no].times.push_back(time); // CPU time taken.
 | ||
|  |     ti.stop(); | ||
|  |     if (time < root_infos[type_no].min_time) | ||
|  |     { | ||
|  |       root_infos[type_no].min_time = time; | ||
|  |     } | ||
|  |     long int distance = static_cast<int>(boost::math::float_distance<T>(result, ans)); | ||
|  |     root_infos[type_no].distances.push_back(distance); | ||
|  |     root_infos[type_no].iterations.push_back(iters); // 
 | ||
|  |     root_infos[type_no].full_results.push_back(result); | ||
|  |   } | ||
|  | 
 | ||
|  |   { | ||
|  |    // algorithm_names.push_back("Shroeder"); // algorithm
 | ||
|  |     cpu_timer ti; // Can start, pause, resume and stop, and read elapsed.
 | ||
|  |     ti.start(); | ||
|  |     for (long i = 0; i < count; ++i) | ||
|  |     { | ||
|  |       result = cbrt_2deriv_s(to_root); // 
 | ||
|  |       sum += result; | ||
|  |     } | ||
|  |     now = ti.elapsed(); | ||
|  | //    int time = static_cast<int>(now.user / count);
 | ||
|  |     long time = static_cast<long>(now.user/1000); | ||
|  |     root_infos[type_no].times.push_back(time); // CPU time taken.
 | ||
|  |     if (time < root_infos[type_no].min_time) | ||
|  |     { | ||
|  |       root_infos[type_no].min_time = time; | ||
|  |     } | ||
|  |     ti.stop(); | ||
|  |     long int distance = static_cast<int>(boost::math::float_distance<T>(result, ans)); | ||
|  |     root_infos[type_no].distances.push_back(distance); | ||
|  |     root_infos[type_no].iterations.push_back(iters); // 
 | ||
|  |     root_infos[type_no].full_results.push_back(result); | ||
|  |   } | ||
|  |   for (size_t i = 0; i != root_infos[type_no].times.size(); i++) | ||
|  |   { // Normalize times.
 | ||
|  |     double normed_time = static_cast<double>(root_infos[type_no].times[i]); | ||
|  |     normed_time /= root_infos[type_no].min_time; | ||
|  |     root_infos[type_no].normed_times.push_back(normed_time); | ||
|  |   } | ||
|  |   algo++; | ||
|  |   std::cout << "Accumulated sum was " << sum << std::endl; | ||
|  |   return algo;  // Count of how many algorithms used.
 | ||
|  | } // test_root
 | ||
|  | 
 | ||
|  | void table_root_info(cpp_bin_float_100 full_value, cpp_bin_float_100 full_answer) | ||
|  | { | ||
|  |    // Fill the elements. 
 | ||
|  |   int type_count = 0; | ||
|  |   type_count = test_root<float>(full_value, full_answer, "float"); | ||
|  |   type_count = test_root<double>(full_value, full_answer, "double"); | ||
|  |   type_count = test_root<long double>(full_value, full_answer, "long double"); | ||
|  |   type_count = test_root<cpp_bin_float_50>(full_value, full_answer, "cpp_bin_float_50"); | ||
|  |   //type_count = test_root<cpp_bin_float_100>(full_value, full_answer, "cpp_bin_float_100");
 | ||
|  | 
 | ||
|  |   std::cout << root_infos.size() << " floating-point types tested:" << std::endl; | ||
|  | #ifndef NDEBUG
 | ||
|  |   std::cout << "Compiled in debug mode." << std::endl; | ||
|  | #else
 | ||
|  |   std::cout << "Compiled in optimise mode." << std::endl; | ||
|  | #endif
 | ||
|  | 
 | ||
|  | 
 | ||
|  |   for (size_t tp = 0; tp != root_infos.size(); tp++) | ||
|  |   { // For all types:
 | ||
|  | 
 | ||
|  |     std::cout << std::endl; | ||
|  | 
 | ||
|  |     std::cout << "Floating-point type = " << root_infos[tp].short_typename << std::endl; | ||
|  |     std::cout << "Floating-point type = " << root_infos[tp].full_typename << std::endl; | ||
|  |     std::cout << "Max_digits10 = " << root_infos[tp].max_digits10 << std::endl; | ||
|  |     std::cout << "Binary digits = " << root_infos[tp].bin_digits << std::endl; | ||
|  |     std::cout << "Accuracy digits = " << root_infos[tp].get_digits - 2 << ", " << static_cast<int>(root_infos[tp].get_digits * 0.6) << ", " << static_cast<int>(root_infos[tp].get_digits * 0.4) << std::endl; | ||
|  |     std::cout << "min_time = " << root_infos[tp].min_time << std::endl; | ||
|  | 
 | ||
|  |     std::cout << std::setprecision(root_infos[tp].max_digits10 ) << "Roots = "; | ||
|  |     std::copy(root_infos[tp].full_results.begin(), root_infos[tp].full_results.end(), std::ostream_iterator<cpp_bin_float_100>(std::cout, " ")); | ||
|  |     std::cout << std::endl; | ||
|  | 
 | ||
|  |     // Header row.
 | ||
|  |     std::cout << "Algorithm         " << "Iterations  " << "Times  " << "Norm_times  " << "Distance" << std::endl; | ||
|  |     std::vector<std::string>::iterator al_iter = algo_names.begin(); | ||
|  | 
 | ||
|  |     // Row for all algorithms.
 | ||
|  |     for (int algo = 0; algo != algo_names.size(); algo++) | ||
|  |     {  | ||
|  |       std::cout | ||
|  |         << std::left << std::setw(20) << algo_names[algo] << "  " | ||
|  |         << std::setw(8) << std::setprecision(2) << root_infos[tp].iterations[algo] << "  " | ||
|  |         << std::setw(8) << std::setprecision(5) << root_infos[tp].times[algo] << " " | ||
|  |         << std::setw(8) << std::setprecision(3) << root_infos[tp].normed_times[algo] << " " | ||
|  |         << std::setw(8) << std::setprecision(2) << root_infos[tp].distances[algo] | ||
|  |         << std::endl; | ||
|  |     } // for algo
 | ||
|  |   } // for tp
 | ||
|  | 
 | ||
|  |   // Print info as Quickbook table.
 | ||
|  | #if 0
 | ||
|  |   fout << "[table:cbrt_5  Info for float, double, long double and cpp_bin_float_50\n" | ||
|  |     << "[[type name] [max_digits10] [binary digits] [required digits]]\n";// header.
 | ||
|  | 
 | ||
|  |   for (size_t tp = 0; tp != root_infos.size(); tp++) | ||
|  |   { // For all types:
 | ||
|  |     fout << "[" | ||
|  |      <<  "[" << root_infos[tp].short_typename << "]"  | ||
|  |       << "[" << root_infos[tp].max_digits10 << "]"  // max_digits10
 | ||
|  |       << "["  << root_infos[tp].bin_digits << "]"// < "Binary digits 
 | ||
|  |       << "["  << root_infos[tp].get_digits << "]]\n"; // Accuracy digits.
 | ||
|  |   } // tp
 | ||
|  |   fout << "] [/table cbrt_5] \n" << std::endl; | ||
|  | #endif
 | ||
|  |   // Prepare Quickbook table of floating-point types.
 | ||
|  |   fout << "[table:cbrt_4 Cube root(28) for float, double, long double and cpp_bin_float_50\n" | ||
|  |     << "[[][float][][][] [][double][][][] [][long d][][][] [][cpp50][][]]\n" | ||
|  |     << "[[Algorithm]";  | ||
|  |   for (size_t tp = 0; tp != root_infos.size(); tp++) | ||
|  |   { // For all types:
 | ||
|  |     fout << "[Its]" << "[Times]" << "[Norm]" << "[Dis]" << "[ ]"; | ||
|  |   } | ||
|  |   fout << "]" << std::endl; | ||
|  | 
 | ||
|  |   // Row for all algorithms.
 | ||
|  |   for (int algo = 0; algo != algo_names.size(); algo++) | ||
|  |   { | ||
|  |     fout << "[[" << std::left << std::setw(9) << algo_names[algo] << "]"; | ||
|  |     for (size_t tp = 0; tp != root_infos.size(); tp++) | ||
|  |     { // For all types:
 | ||
|  | 
 | ||
|  |        fout | ||
|  |           << "[" << std::right << std::showpoint | ||
|  |           << std::setw(3) << std::setprecision(2) << root_infos[tp].iterations[algo] << "][" | ||
|  |           << std::setw(5) << std::setprecision(5) << root_infos[tp].times[algo] << "]["; | ||
|  |        if(fabs(root_infos[tp].normed_times[algo]) <= 1.05) | ||
|  |           fout << "[role blue " << std::setw(3) << std::setprecision(2) << root_infos[tp].normed_times[algo] << "]"; | ||
|  |        else if(fabs(root_infos[tp].normed_times[algo]) > 4) | ||
|  |           fout << "[role red " << std::setw(3) << std::setprecision(2) << root_infos[tp].normed_times[algo] << "]"; | ||
|  |        else | ||
|  |           fout << std::setw(3) << std::setprecision(2) << root_infos[tp].normed_times[algo]; | ||
|  |        fout | ||
|  |         << "][" | ||
|  |         << std::setw(3) << std::setprecision(2) << root_infos[tp].distances[algo] << "][ ]"; | ||
|  |     } // tp
 | ||
|  |      fout <<"]" << std::endl; | ||
|  |   } // for algo
 | ||
|  |   fout << "] [/end of table cbrt_4]\n"; | ||
|  | } // void table_root_info
 | ||
|  | 
 | ||
|  | int main() | ||
|  | { | ||
|  |   using namespace boost::multiprecision; | ||
|  |   using namespace boost::math; | ||
|  |   | ||
|  |   try | ||
|  |   { | ||
|  |     std::cout << "Tests run with " << BOOST_COMPILER << ", " | ||
|  |       << BOOST_STDLIB << ", " << BOOST_PLATFORM << ", "; | ||
|  | 
 | ||
|  |     if (fout.is_open()) | ||
|  |     { | ||
|  |       std::cout << "\nOutput to " << filename << std::endl; | ||
|  |     } | ||
|  |     else | ||
|  |     { // Failed to open.
 | ||
|  |       std::cout << " Open file " << filename << " for output failed!" << std::endl; | ||
|  |       std::cout << "error" << errno << std::endl; | ||
|  |       return boost::exit_failure; | ||
|  |     } | ||
|  | 
 | ||
|  |     fout << | ||
|  |       "[/""\n" | ||
|  |       "Copyright 2015 Paul A. Bristow.""\n" | ||
|  |       "Copyright 2015 John Maddock.""\n" | ||
|  |       "Distributed under the Boost Software License, Version 1.0.""\n" | ||
|  |       "(See accompanying file LICENSE_1_0.txt or copy at""\n" | ||
|  |       "http://www.boost.org/LICENSE_1_0.txt).""\n" | ||
|  |       "]""\n" | ||
|  |       << std::endl; | ||
|  |     std::string debug_or_optimize; | ||
|  | #ifdef _DEBUG
 | ||
|  | #if (_DEBUG == 0)
 | ||
|  |     debug_or_optimize = "Compiled in debug mode."; | ||
|  | #else
 | ||
|  |     debug_or_optimize = "Compiled in optimise mode."; | ||
|  | #endif
 | ||
|  | #endif
 | ||
|  | 
 | ||
|  |     // Print out the program/compiler/stdlib/platform names as a Quickbook comment:
 | ||
|  |     fout << "\n[h5 Program " << short_file_name(sourcefilename) << ", " | ||
|  |       << BOOST_COMPILER << ", " | ||
|  |       << BOOST_STDLIB << ", " | ||
|  |       << BOOST_PLATFORM << (sizeof(void*) == 8 ? ", x64" : ", x86") | ||
|  |       << debug_or_optimize << "[br]" | ||
|  |       << count << " evaluations of each of " << algo_names.size() << " root_finding algorithms." | ||
|  |       << "]" | ||
|  |       << std::endl; | ||
|  |      | ||
|  |     std::cout << count << " evaluations of root_finding." << std::endl; | ||
|  | 
 | ||
|  |     BOOST_MATH_CONTROL_FP; | ||
|  | 
 | ||
|  |     cpp_bin_float_100 full_value("28"); | ||
|  | 
 | ||
|  |     cpp_bin_float_100 full_answer ("3.036588971875662519420809578505669635581453977248111123242141654169177268411884961770250390838097895"); | ||
|  | 
 | ||
|  |     std::copy(max_digits10s.begin(), max_digits10s.end(), std::ostream_iterator<int>(std::cout, " ")); | ||
|  |     std::cout << std::endl; | ||
|  | 
 | ||
|  |     table_root_info(full_value, full_answer); | ||
|  | 
 | ||
|  | 
 | ||
|  |     return boost::exit_success; | ||
|  |   } | ||
|  |   catch (std::exception ex) | ||
|  |   { | ||
|  |     std::cout << "exception thrown: " << ex.what() << std::endl; | ||
|  |     return boost::exit_failure; | ||
|  |   } | ||
|  | } // int main()
 | ||
|  | 
 | ||
|  | /*
 | ||
|  | debug | ||
|  | 
 | ||
|  | 1>  float, maxdigits10 = 9 | ||
|  | 1>  6 algorithms used. | ||
|  | 1>  Digits required = 24.0000000 | ||
|  | 1>  find root of 28.0000000, expected answer = 3.03658897 | ||
|  | 1>  Times 156 312 18750 4375 3437 3906 | ||
|  | 1>  Iterations: 0 0 8 6 4 5 | ||
|  | 1>  Distance: 0 0 -1 0 0 0 | ||
|  | 1>  Roots: 3.03658891 3.03658891 3.03658915 3.03658891 3.03658891 3.03658891 | ||
|  | 
 | ||
|  | release | ||
|  | 
 | ||
|  | 1>  float, maxdigits10 = 9 | ||
|  | 1>  6 algorithms used. | ||
|  | 1>  Digits required = 24.0000000 | ||
|  | 1>  find root of 28.0000000, expected answer = 3.03658897 | ||
|  | 1>  Times 0 312 6875 937 937 937 | ||
|  | 1>  Iterations: 0 0 8 6 4 5 | ||
|  | 1>  Distance: 0 0 -1 0 0 0 | ||
|  | 1>  Roots: 3.03658891 3.03658891 3.03658915 3.03658891 3.03658891 3.03658891 | ||
|  | 
 | ||
|  | 
 | ||
|  | 1> | ||
|  | 1>  5 algorithms used: | ||
|  | 1>  10 algorithms used: | ||
|  | 1>  boost::math::cbrt TOMS748 Newton Halley Shroeder boost::math::cbrt TOMS748 Newton Halley Shroeder | ||
|  | 1>  2 types compared. | ||
|  | 1>  Precision of full type = 102 decimal digits | ||
|  | 1>  Find root of 28.000000000000000, | ||
|  | 1>  Expected answer = 3.0365889718756625 | ||
|  | 1>  typeid(T).name()float, maxdigits10 = 9 | ||
|  | 1>  find root of 28.0000000, expected answer = 3.03658897 | ||
|  | 1> | ||
|  | 1>  Iterations: 0 8 6 4 5 | ||
|  | 1>  Times 468 8437 4375 3593 4062 | ||
|  | 1>  Min Time 468 | ||
|  | 1>  Normalized Times 1.00 18.0 9.35 7.68 8.68 | ||
|  | 1>  Distance: 0 -1 0 0 0 | ||
|  | 1>  Roots: 3.03658891 3.03658915 3.03658891 3.03658891 3.03658891 | ||
|  | 1>  ================================================================== | ||
|  | 1>  typeid(T).name()double, maxdigits10 = 17 | ||
|  | 1>  find root of 28.000000000000000, expected answer = 3.0365889718756625 | ||
|  | 1> | ||
|  | 1>  Iterations: 0 11 7 5 6 | ||
|  | 1>  Times 312 15000 4531 3906 4375 | ||
|  | 1>  Min Time 312 | ||
|  | 1>  Normalized Times 1.00 48.1 14.5 12.5 14.0 | ||
|  | 1>  Distance: 1 2 0 0 0 | ||
|  | 1>  Roots: 3.0365889718756622 3.0365889718756618 3.0365889718756627 3.0365889718756627 3.0365889718756627 | ||
|  | 1>  ================================================================== | ||
|  | 
 | ||
|  | 
 | ||
|  | Release | ||
|  | 
 | ||
|  | 1>  5 algorithms used: | ||
|  | 1>  10 algorithms used: | ||
|  | 1>  boost::math::cbrt TOMS748 Newton Halley Shroeder boost::math::cbrt TOMS748 Newton Halley Shroeder | ||
|  | 1>  2 types compared. | ||
|  | 1>  Precision of full type = 102 decimal digits | ||
|  | 1>  Find root of 28.000000000000000, | ||
|  | 1>  Expected answer = 3.0365889718756625 | ||
|  | 1>  typeid(T).name()float, maxdigits10 = 9 | ||
|  | 1>  find root of 28.0000000, expected answer = 3.03658897 | ||
|  | 1> | ||
|  | 1>  Iterations: 0 8 6 4 5 | ||
|  | 1>  Times 312 781 937 937 937 | ||
|  | 1>  Min Time 312 | ||
|  | 1>  Normalized Times 1.00 2.50 3.00 3.00 3.00 | ||
|  | 1>  Distance: 0 -1 0 0 0 | ||
|  | 1>  Roots: 3.03658891 3.03658915 3.03658891 3.03658891 3.03658891 | ||
|  | 1>  ================================================================== | ||
|  | 1>  typeid(T).name()double, maxdigits10 = 17 | ||
|  | 1>  find root of 28.000000000000000, expected answer = 3.0365889718756625 | ||
|  | 1> | ||
|  | 1>  Iterations: 0 11 7 5 6 | ||
|  | 1>  Times 312 1093 937 937 937 | ||
|  | 1>  Min Time 312 | ||
|  | 1>  Normalized Times 1.00 3.50 3.00 3.00 3.00 | ||
|  | 1>  Distance: 1 2 0 0 0 | ||
|  | 1>  Roots: 3.0365889718756622 3.0365889718756618 3.0365889718756627 3.0365889718756627 3.0365889718756627 | ||
|  | 1>  ================================================================== | ||
|  | 
 | ||
|  | 
 | ||
|  | 
 | ||
|  | 1>  5 algorithms used: | ||
|  | 1>  15 algorithms used: | ||
|  | 1>  boost::math::cbrt TOMS748 Newton Halley Shroeder boost::math::cbrt TOMS748 Newton Halley Shroeder boost::math::cbrt TOMS748 Newton Halley Shroeder | ||
|  | 1>  3 types compared. | ||
|  | 1>  Precision of full type = 102 decimal digits | ||
|  | 1>  Find root of 28.00000000000000000000000000000000000000000000000000, | ||
|  | 1>  Expected answer = 3.036588971875662519420809578505669635581453977248111 | ||
|  | 1>  typeid(T).name()float, maxdigits10 = 9 | ||
|  | 1>  find root of 28.0000000, expected answer = 3.03658897 | ||
|  | 1> | ||
|  | 1>  Iterations: 0 8 6 4 5 | ||
|  | 1>  Times 156 781 937 1093 937 | ||
|  | 1>  Min Time 156 | ||
|  | 1>  Normalized Times 1.00 5.01 6.01 7.01 6.01 | ||
|  | 1>  Distance: 0 -1 0 0 0 | ||
|  | 1>  Roots: 3.03658891 3.03658915 3.03658891 3.03658891 3.03658891 | ||
|  | 1>  ================================================================== | ||
|  | 1>  typeid(T).name()double, maxdigits10 = 17 | ||
|  | 1>  find root of 28.000000000000000, expected answer = 3.0365889718756625 | ||
|  | 1> | ||
|  | 1>  Iterations: 0 11 7 5 6 | ||
|  | 1>  Times 312 1093 937 937 937 | ||
|  | 1>  Min Time 312 | ||
|  | 1>  Normalized Times 1.00 3.50 3.00 3.00 3.00 | ||
|  | 1>  Distance: 1 2 0 0 0 | ||
|  | 1>  Roots: 3.0365889718756622 3.0365889718756618 3.0365889718756627 3.0365889718756627 3.0365889718756627 | ||
|  | 1>  ================================================================== | ||
|  | 1>  typeid(T).name()class boost::multiprecision::number<class boost::multiprecision::backends::cpp_bin_float<50,10,void,int,0,0>,0>, maxdigits10 = 52 | ||
|  | 1>  find root of 28.00000000000000000000000000000000000000000000000000, expected answer = 3.036588971875662519420809578505669635581453977248111 | ||
|  | 1> | ||
|  | 1>  Iterations: 0 13 9 6 7 | ||
|  | 1>  Times 8750 177343 30312 52968 58125 | ||
|  | 1>  Min Time 8750 | ||
|  | 1>  Normalized Times 1.00 20.3 3.46 6.05 6.64 | ||
|  | 1>  Distance: 0 0 -1 0 0 | ||
|  | 1>  Roots: 3.036588971875662519420809578505669635581453977248106 3.036588971875662519420809578505669635581453977248106 3.036588971875662519420809578505669635581453977248117 3.036588971875662519420809578505669635581453977248106 3.036588971875662519420809578505669635581453977248106 | ||
|  | 1>  ================================================================== | ||
|  | 
 | ||
|  | Reduce accuracy required to 0.5 | ||
|  | 
 | ||
|  | 1>  5 algorithms used: | ||
|  | 1>  15 algorithms used: | ||
|  | 1>  boost::math::cbrt TOMS748 Newton Halley Shroeder | ||
|  | 1>  3 floating_point types compared. | ||
|  | 1>  Precision of full type = 102 decimal digits | ||
|  | 1>  Find root of 28.00000000000000000000000000000000000000000000000000, | ||
|  | 1>  Expected answer = 3.036588971875662519420809578505669635581453977248111 | ||
|  | 1>  typeid(T).name() = float, maxdigits10 = 9 | ||
|  | 1>  Digits accuracy fraction required = 0.500000000 | ||
|  | 1>  find root of 28.0000000, expected answer = 3.03658897 | ||
|  | 1> | ||
|  | 1>  Iterations: 0 8 5 3 4 | ||
|  | 1>  Times 156 5937 1406 1250 1250 | ||
|  | 1>  Min Time 156 | ||
|  | 1>  Normalized Times 1.0 38. 9.0 8.0 8.0 | ||
|  | 1>  Distance: 0 -1 0 0 0 | ||
|  | 1>  Roots: 3.03658891 3.03658915 3.03658891 3.03658891 3.03658891 | ||
|  | 1>  ================================================================== | ||
|  | 1>  typeid(T).name() = double, maxdigits10 = 17 | ||
|  | 1>  Digits accuracy fraction required = 0.50000000000000000 | ||
|  | 1>  find root of 28.000000000000000, expected answer = 3.0365889718756625 | ||
|  | 1> | ||
|  | 1>  Iterations: 0 8 6 4 5 | ||
|  | 1>  Times 156 6250 1406 1406 1250 | ||
|  | 1>  Min Time 156 | ||
|  | 1>  Normalized Times 1.0 40. 9.0 9.0 8.0 | ||
|  | 1>  Distance: 1 3695766 0 0 0 | ||
|  | 1>  Roots: 3.0365889718756622 3.0365889702344129 3.0365889718756627 3.0365889718756627 3.0365889718756627 | ||
|  | 1>  ================================================================== | ||
|  | 1>  typeid(T).name() = class boost::multiprecision::number<class boost::multiprecision::backends::cpp_bin_float<50,10,void,int,0,0>,0>, maxdigits10 = 52 | ||
|  | 1>  Digits accuracy fraction required = 0.5000000000000000000000000000000000000000000000000000 | ||
|  | 1>  find root of 28.00000000000000000000000000000000000000000000000000, expected answer = 3.036588971875662519420809578505669635581453977248111 | ||
|  | 1> | ||
|  | 1>  Iterations: 0 11 8 5 6 | ||
|  | 1>  Times 11562 239843 34843 47500 47812 | ||
|  | 1>  Min Time 11562 | ||
|  | 1>  Normalized Times 1.0 21. 3.0 4.1 4.1 | ||
|  | 1>  Distance: 0 0 -1 0 0 | ||
|  | 1>  Roots: 3.036588971875662519420809578505669635581453977248106 3.036588971875662519420809578505669635581453977248106 3.036588971875662519420809578505669635581453977248117 3.036588971875662519420809578505669635581453977248106 3.036588971875662519420809578505669635581453977248106 | ||
|  | 1>  ================================================================== | ||
|  | 
 | ||
|  | 
 | ||
|  | 
 | ||
|  | */ |