86 lines
2.3 KiB
C++
86 lines
2.3 KiB
C++
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// Copyright Christopher Kormanyos 2013.
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// Copyright Paul A. Bristow 2013.
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// Copyright John Maddock 2013.
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// Distributed under the Boost Software License, Version 1.0.
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// (See accompanying file LICENSE_1_0.txt or
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// copy at http://www.boost.org/LICENSE_1_0.txt).
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#ifdef _MSC_VER
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# pragma warning (disable : 4512) // assignment operator could not be generated.
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# pragma warning (disable : 4996) // assignment operator could not be generated.
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#endif
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#include <iostream>
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#include <limits>
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#include <vector>
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#include <algorithm>
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#include <iomanip>
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#include <iterator>
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//[neumann_zeros_example_1
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/*`[h5 Calculating zeros of the Neumann function.]
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This example also shows how Boost.Math and Boost.Multiprecision can be combined to provide
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a many decimal digit precision. For 50 decimal digit precision we need to include
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*/
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#include <boost/multiprecision/cpp_dec_float.hpp>
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/*`and a `typedef` for `float_type` may be convenient
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(allowing a quick switch to re-compute at built-in `double` or other precision)
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*/
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typedef boost::multiprecision::cpp_dec_float_50 float_type;
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//`To use the functions for finding zeros of the `cyl_neumann` function we need:
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#include <boost/math/special_functions/bessel.hpp>
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//] [/neumann_zerso_example_1]
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int main()
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{
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try
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{
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{
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//[neumann_zeros_example_2
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/*`The Neumann (Bessel Y) function zeros are evaluated very similarly:
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*/
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using boost::math::cyl_neumann_zero;
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double zn = cyl_neumann_zero(2., 1);
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std::cout << "cyl_neumann_zero(2., 1) = " << zn << std::endl;
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std::vector<float> nzeros(3); // Space for 3 zeros.
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cyl_neumann_zero<float>(2.F, 1, nzeros.size(), nzeros.begin());
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std::cout << "cyl_neumann_zero<float>(2.F, 1, ";
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// Print the zeros to the output stream.
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std::copy(nzeros.begin(), nzeros.end(),
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std::ostream_iterator<float>(std::cout, ", "));
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std::cout << "\n""cyl_neumann_zero(static_cast<float_type>(220)/100, 1) = "
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<< cyl_neumann_zero(static_cast<float_type>(220)/100, 1) << std::endl;
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// 3.6154383428745996706772556069431792744372398748422
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//] //[/neumann_zeros_example_2]
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}
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}
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catch (std::exception const& ex)
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{
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std::cout << "Thrown exception " << ex.what() << std::endl;
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}
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} // int main()
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/*
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Output:
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cyl_neumann_zero(2., 1) = 3.38424
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cyl_neumann_zero<float>(2.F, 1,
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3.38424
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6.79381
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10.0235
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3.61544
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*/
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