mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-29 15:48:38 -05:00
270 lines
9.9 KiB
C++
270 lines
9.9 KiB
C++
/** nonfinite_num_facet.cpp
|
|
*
|
|
* Copyright (c) 2011 Paul A. Bristow
|
|
*
|
|
* 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)
|
|
*
|
|
* This very simple program illustrates how to use the
|
|
* `boost/math/nonfinite_num_facets.hpp' to obtain C99
|
|
* representation of infinity and NaN.
|
|
* (from the original
|
|
* Floating Point Utilities contribution by Johan Rade.
|
|
* Floating Point Utility library has been accepted into Boost,
|
|
* but the utilities are incorporated into Boost.Math library.
|
|
*
|
|
\file
|
|
|
|
\brief A very simple example of using non_finite_num facet for
|
|
C99 standard output of infinity and NaN.
|
|
|
|
\detail Provided infinity and nan are supported,
|
|
this example shows how to create a C99 non-finite locale,
|
|
and imbue input and output streams with the non_finite_num put and get facets.
|
|
This allow output and input of infinity and NaN in a Standard portable way,
|
|
This permits 'loop-back' of output back into input (and portably across different system too).
|
|
This is particularly useful when used with Boost.Serialization so that non-finite NaNs and infinity
|
|
values in text and xml archives can be handled correctly and portably.
|
|
|
|
*/
|
|
|
|
#ifdef _MSC_VER
|
|
# pragma warning (disable : 4127) // conditional expression is constant.
|
|
#endif
|
|
|
|
#include <iostream>
|
|
using std::cout;
|
|
using std::endl;
|
|
using std::cerr;
|
|
|
|
#include <iomanip>
|
|
using std::setw;
|
|
using std::left;
|
|
using std::right;
|
|
using std::internal;
|
|
|
|
#include <string>
|
|
using std::string;
|
|
|
|
#include <sstream>
|
|
using std::istringstream;
|
|
|
|
#include <limits>
|
|
using std::numeric_limits;
|
|
|
|
#include <locale>
|
|
using std::locale;
|
|
|
|
#include <boost/math/special_functions/nonfinite_num_facets.hpp>
|
|
// from Johan Rade Floating Point Utilities.
|
|
|
|
int main ()
|
|
{
|
|
std::cout << "Nonfinite_num_facet very simple example." << std::endl;
|
|
|
|
if((std::numeric_limits<double>::has_infinity == 0) || (std::numeric_limits<double>::infinity() == 0))
|
|
{
|
|
std::cout << "Infinity not supported on this platform." << std::endl;
|
|
return 0;
|
|
}
|
|
|
|
if((std::numeric_limits<double>::has_quiet_NaN == 0) || (std::numeric_limits<double>::quiet_NaN() == 0))
|
|
{
|
|
std::cout << "NaN not supported on this platform." << std::endl;
|
|
return 0;
|
|
}
|
|
|
|
std::locale default_locale (std::locale::classic ()); // Note the currrent (default C) locale.
|
|
|
|
// Create plus and minus infinity.
|
|
double plus_infinity = +std::numeric_limits<double>::infinity();
|
|
double minus_infinity = -std::numeric_limits<double>::infinity();
|
|
|
|
// and create a NaN (NotANumber)
|
|
double NaN = +std::numeric_limits<double>::quiet_NaN ();
|
|
|
|
double negated_NaN = (boost::math::changesign)(std::numeric_limits<double>::quiet_NaN ());
|
|
|
|
|
|
// Output the nonfinite values using the current (default C) locale.
|
|
// The default representations differ from system to system,
|
|
// for example, using Microsoft compilers, 1.#INF, -1.#INF, and 1.#QNAN,
|
|
// Linux "inf", "-inf", "nan"
|
|
cout << "Using C locale" << endl;
|
|
cout << "+std::numeric_limits<double>::infinity() = " << plus_infinity << endl;
|
|
cout << "-std::numeric_limits<double>::infinity() = " << minus_infinity << endl;
|
|
cout << "+std::numeric_limits<double>::quiet_NaN () = " << NaN << endl;
|
|
|
|
// Display negated NaN.
|
|
cout << "negated NaN " << negated_NaN << endl; // "-1.IND" or "-nan".
|
|
|
|
// Create a new output locale, and add the nonfinite_num_put facet
|
|
std::locale C99_out_locale (default_locale, new boost::math::nonfinite_num_put<char>);
|
|
// and imbue the cout stream with the new locale.
|
|
cout.imbue (C99_out_locale);
|
|
|
|
// Or for the same effect more concisely:
|
|
cout.imbue (locale(locale(), new boost::math::nonfinite_num_put<char>));
|
|
|
|
// Output using the new locale:
|
|
cout << "Using C99_out_locale " << endl;
|
|
cout << "+std::numeric_limits<double>::infinity() = " << plus_infinity << endl;
|
|
cout << "-std::numeric_limits<double>::infinity() = " << minus_infinity << endl;
|
|
cout << "+std::numeric_limits<double>::quiet_NaN () = " << NaN << endl;
|
|
// Expect "inf", "-inf", "nan".
|
|
|
|
// Display negated NaN.
|
|
cout << "negated NaN " << negated_NaN << endl; // Expect "-nan".
|
|
|
|
// Create a string with the expected C99 representation of plus infinity.
|
|
std::string inf = "inf";
|
|
{ // Try to read an infinity value using the default C locale.
|
|
// Create an input stream which will provide "inf"
|
|
std::istringstream iss (inf);
|
|
|
|
// Create a double ready to take the input,
|
|
double infinity;
|
|
// and read "inf" from the stringstream:
|
|
iss >> infinity;
|
|
|
|
// This will not work on all platforms! (Intel-Linux-13.0.1 fails EXIT STATUS: 139)
|
|
if (! iss)
|
|
{ // Reading infinity went wrong!
|
|
std::cerr << "C locale input format error!" << std::endl;
|
|
}
|
|
} // Using default C locale.
|
|
|
|
{ // Now retry using C99 facets.
|
|
// Create a new input locale and add the nonfinite_num_get facet.
|
|
std::locale C99_in_locale (default_locale, new boost::math::nonfinite_num_get<char>);
|
|
|
|
// Create an input stream which will provide "inf".
|
|
std::istringstream iss (inf);
|
|
// Imbue the stream with the C99 input locale.
|
|
iss.imbue (C99_in_locale);
|
|
|
|
// Create a double ready to take the input,
|
|
double infinity;
|
|
// and read from the stringstream:
|
|
iss >> infinity;
|
|
|
|
if (! iss)
|
|
{ // Reading infinity went wrong!
|
|
std::cout << "C99 input format error!" << std::endl;
|
|
}
|
|
// Expect to get an infinity, which will display still using the C99 locale as "inf"
|
|
cout << "infinity in C99 representation is " << infinity << endl;
|
|
|
|
// To check, we can switch back to the default C locale.
|
|
cout.imbue (default_locale);
|
|
cout << "infinity in default C representation is " << infinity << endl;
|
|
} // using C99 locale.
|
|
|
|
{
|
|
// A 'loop-back example, output to a stringstream, and reading it back in.
|
|
// Create C99 input and output locales.
|
|
std::locale C99_out_locale (default_locale, new boost::math::nonfinite_num_put<char>);
|
|
std::locale C99_in_locale (default_locale, new boost::math::nonfinite_num_get<char>);
|
|
|
|
std::ostringstream oss;
|
|
oss.imbue(C99_out_locale);
|
|
oss << plus_infinity;
|
|
|
|
std::istringstream iss(oss.str()); // So stream contains "inf".
|
|
iss.imbue (C99_in_locale);
|
|
|
|
std::string s;
|
|
|
|
iss >> s;
|
|
|
|
cout.imbue(C99_out_locale);
|
|
if (oss.str() != s)
|
|
{
|
|
cout << plus_infinity << " != " << s << " loopback failed!" << endl;
|
|
}
|
|
else
|
|
{
|
|
cout << plus_infinity << " == " << s << " as expected." << endl;
|
|
}
|
|
}
|
|
|
|
|
|
// Example varying the width and position of the nonfinite representations.
|
|
// With the nonfinite_num_put and _get facets, the width of the output is constant.
|
|
|
|
#ifdef BOOST_NO_CXX11_NUMERIC_LIMITS
|
|
cout << "BOOST_NO_CXX11_NUMERIC_LIMITS is defined, so no max_digits10 available." << endl;
|
|
std::streamsize max_digits10 = 2 + std::numeric_limits<double>::digits * 30103UL / 100000UL;
|
|
#else
|
|
// Can use new C++0X max_digits10 (the maximum potentially significant digits).
|
|
std::streamsize max_digits10 = std::numeric_limits<double>::max_digits10;
|
|
#endif
|
|
cout << "std::numeric_limits<double>::max_digits10 is " << max_digits10 << endl;
|
|
cout.precision(max_digits10);
|
|
|
|
double pi = 3.141592653589793238462643383279502884197169399375105820974944;
|
|
// Expect 17 (probably) decimal digits (regardless of locale).
|
|
// cout has the default locale.
|
|
cout << "pi = " << pi << endl; // pi = 3.1415926535897931
|
|
cout.imbue (C99_out_locale); // Use cout with the C99 locale
|
|
// (expect the same output for a double).
|
|
cout << "pi = " << pi << endl; // pi = 3.1415926535897931
|
|
|
|
cout << "infinity in C99 representation is " << plus_infinity << endl;
|
|
|
|
//int width = 2; // Check effect if width too small is OK.
|
|
// (There was a disturbed layout on older MSVC?).
|
|
int width = 20;
|
|
|
|
// Similarly if we can switch back to the default C locale.
|
|
cout.imbue (default_locale);
|
|
cout << "infinity in default C representation is " << plus_infinity << endl;
|
|
cout << "infinity in default C representation (setw(" << width << ") is |" << setw(width) << plus_infinity <<'|' << endl;
|
|
cout << "infinity in default C representation (setw(" << width << ") is |" << left << setw(width) << plus_infinity <<'|' << endl;
|
|
cout << "infinity in default C representation (setw(" << width << ") is |" << internal << setw(width) << plus_infinity <<'|' << endl;
|
|
|
|
cout.imbue (C99_out_locale);
|
|
cout << "infinity in C99 representation (setw(" << width << ") is |" << right << setw(width) << plus_infinity <<'|'<< endl;
|
|
cout << "infinity in C99 representation (setw(" << width << ") is |" << left << setw(width) << plus_infinity <<'|'<< endl;
|
|
cout << "infinity in C99 representation (setw(" << width << ") is |" << internal << setw(width) << plus_infinity <<'|'<< endl;
|
|
|
|
return 0;
|
|
} // int main()
|
|
|
|
// end of test_nonfinite_num_facets.cpp
|
|
|
|
/*
|
|
|
|
Output:
|
|
|
|
simple_nonfinite_facet.vcxproj -> J:\Cpp\MathToolkit\test\Math_test\Release\nonfinite_facet_simple.exe
|
|
Nonfinite_num_facet very simple example.
|
|
Using C locale
|
|
+std::numeric_limits<double>::infinity() = 1.#INF
|
|
-std::numeric_limits<double>::infinity() = -1.#INF
|
|
+std::numeric_limits<double>::quiet_NaN () = 1.#QNAN
|
|
Using C99_out_locale
|
|
+std::numeric_limits<double>::infinity() = inf
|
|
-std::numeric_limits<double>::infinity() = -inf
|
|
+std::numeric_limits<double>::quiet_NaN () = nan
|
|
infinity in C99 representation is inf
|
|
infinity in default C representation is 1.#INF
|
|
3
|
|
3
|
|
inf == inf as expected.
|
|
std::numeric_limits<double>::max_digits10 is 17
|
|
pi = 3.1415926535897931
|
|
C locale input format error!
|
|
pi = 3.1415926535897931
|
|
infinity in C99 representation is inf
|
|
infinity in default C representation is 1.#INF
|
|
infinity in default C representation (setw(20) is 1.#INF|
|
|
infinity in default C representation (setw(20) is 1.#INF |
|
|
infinity in default C representation (setw(20) is 1.#INF|
|
|
infinity in C99 representation (setw(20) is inf|
|
|
infinity in C99 representation (setw(20) is inf |
|
|
infinity in C99 representation (setw(20) is inf|
|
|
|
|
*/
|