41 lines
1.3 KiB
C++
41 lines
1.3 KiB
C++
///////////////////////////////////////////////////////////////
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// Copyright 2011 John Maddock. Distributed under the Boost
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// Software License, Version 1.0. (See accompanying file
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// LICENSE_1_0.txt or copy at https://www.boost.org/LICENSE_1_0.txt
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//[mpfr_eg
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#include <boost/multiprecision/mpfr.hpp>
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#include <boost/math/special_functions/gamma.hpp>
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#include <iostream>
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int main()
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{
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using namespace boost::multiprecision;
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// Operations at variable precision and no numeric_limits support:
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mpfr_float a = 2;
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mpfr_float::default_precision(1000);
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std::cout << mpfr_float::default_precision() << std::endl;
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std::cout << sqrt(a) << std::endl; // print root-2
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// Operations at fixed precision and full numeric_limits support:
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mpfr_float_100 b = 2;
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std::cout << std::numeric_limits<mpfr_float_100>::digits << std::endl;
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// We can use any C++ std lib function:
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std::cout << log(b) << std::endl; // print log(2)
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// We can also use any function from Boost.Math:
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std::cout << boost::math::tgamma(b) << std::endl;
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// These even work when the argument is an expression template:
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std::cout << boost::math::tgamma(b * b) << std::endl;
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// Access the underlying data:
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mpfr_t r;
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mpfr_init(r);
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mpfr_set(r, b.backend().data(), GMP_RNDN);
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mpfr_clear(r);
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return 0;
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}
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//]
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