123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151 |
- /*
- [auto_generated]
- libs/numeric/odeint/examples/black_hole.cpp
- [begin_description]
- This example shows how the __float128 from gcc libquadmath can be used with odeint.
- [end_description]
- Copyright 2012 Karsten Ahnert
- Copyright 2012 Lee Hodgkinson
- Copyright 2012 Mario Mulansky
- 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)
- */
- #include <cstdlib>
- #include <cmath>
- #include <iostream>
- #include <iterator>
- #include <utility>
- #include <algorithm>
- #include <cassert>
- #include <vector>
- #include <complex>
- extern "C" {
- #include <quadmath.h>
- }
- const __float128 zero =strtoflt128 ("0.0", NULL);
- namespace std {
- inline __float128 abs( __float128 x )
- {
- return fabsq( x );
- }
- inline __float128 sqrt( __float128 x )
- {
- return sqrtq( x );
- }
- inline __float128 pow( __float128 x , __float128 y )
- {
- return powq( x , y );
- }
- inline __float128 abs( std::complex< __float128 > x )
- {
- return sqrtq( x.real() * x.real() + x.imag() * x.imag() );
- }
- inline std::complex< __float128 > pow( std::complex< __float128> x , __float128 y )
- {
- __float128 r = pow( abs(x) , y );
- __float128 phi = atanq( x.imag() / x.real() );
- return std::complex< __float128 >( r * cosq( y * phi ) , r * sinq( y * phi ) );
- }
- }
- inline std::ostream& operator<< (std::ostream& os, const __float128& f) {
- char* y = new char[1000];
- quadmath_snprintf(y, 1000, "%.30Qg", f) ;
- os.precision(30);
- os<<y;
- delete[] y;
- return os;
- }
- #include <boost/array.hpp>
- #include <boost/range/algorithm.hpp>
- #include <boost/range/adaptor/filtered.hpp>
- #include <boost/range/numeric.hpp>
- #include <boost/numeric/odeint.hpp>
- using namespace boost::numeric::odeint;
- using namespace std;
- typedef __float128 my_float;
- typedef std::vector< std::complex < my_float > > state_type;
- struct radMod
- {
- my_float m_om;
- my_float m_l;
- radMod( my_float om , my_float l )
- : m_om( om ) , m_l( l ) { }
- void operator()( const state_type &x , state_type &dxdt , my_float r ) const
- {
- dxdt[0] = x[1];
- dxdt[1] = -(2*(r-1)/(r*(r-2)))*x[1]-((m_om*m_om*r*r/((r-2)*(r-2)))-(m_l*(m_l+1)/(r*(r-2))))*x[0];
- }
- };
- int main( int argc , char **argv )
- {
- state_type x(2);
- my_float re0 = strtoflt128( "-0.00008944230755601224204687038354994353820468" , NULL );
- my_float im0 = strtoflt128( "0.00004472229441850588228136889483397204368247" , NULL );
- my_float re1 = strtoflt128( "-4.464175354293244250869336196695966076150E-6 " , NULL );
- my_float im1 = strtoflt128( "-8.950483248390306670770345406051469584488E-6" , NULL );
- x[0] = complex< my_float >( re0 ,im0 );
- x[1] = complex< my_float >( re1 ,im1 );
- const my_float dt =strtoflt128 ("-0.001", NULL);
- const my_float start =strtoflt128 ("10000.0", NULL);
- const my_float end =strtoflt128 ("9990.0", NULL);
- const my_float omega =strtoflt128 ("2.0", NULL);
- const my_float ell =strtoflt128 ("1.0", NULL);
- my_float abs_err = strtoflt128( "1.0E-15" , NULL ) , rel_err = strtoflt128( "1.0E-10" , NULL );
- my_float a_x = strtoflt128( "1.0" , NULL ) , a_dxdt = strtoflt128( "1.0" , NULL );
- typedef runge_kutta_dopri5< state_type, my_float > dopri5_type;
- typedef controlled_runge_kutta< dopri5_type > controlled_dopri5_type;
- typedef dense_output_runge_kutta< controlled_dopri5_type > dense_output_dopri5_type;
-
- dense_output_dopri5_type dopri5( controlled_dopri5_type( default_error_checker< my_float >( abs_err , rel_err , a_x , a_dxdt ) ) );
- std::for_each( make_adaptive_time_iterator_begin(dopri5 , radMod(omega , ell) , x , start , end , dt) ,
- make_adaptive_time_iterator_end(dopri5 , radMod(omega , ell) , x ) ,
- []( const std::pair< state_type&, my_float > &x ) {
- std::cout << x.second << ", " << x.first[0].real() << "\n"; }
- );
- return 0;
- }
|