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49 lines
998 B
C++
49 lines
998 B
C++
/*
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numerics.cc - This file is part of MUSIC -
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a code to generate multi-scale initial conditions
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for cosmological simulations
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Copyright (C) 2010 Oliver Hahn
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*/
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#ifdef WITH_MPI
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#ifdef MANNO
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#include <mpi.h>
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#else
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#include <mpi++.h>
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#endif
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#endif
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#include <iostream>
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#include "Numerics.hh"
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#ifndef REL_PRECISION
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#define REL_PRECISION 1.e-5
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#endif
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real_t integrate( double (* func) (double x, void * params), double a, double b, void *params )
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{
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gsl_function F;
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F.function = func;
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F.params = params;
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double result;
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double error;
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gsl_set_error_handler_off ();
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gsl_integration_workspace *w = gsl_integration_workspace_alloc(100000);
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gsl_integration_qag( &F, a, b, 0, REL_PRECISION, 100000, 6, w, &result, &error );
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gsl_integration_workspace_free(w);
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gsl_set_error_handler(NULL);
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if( error/result > REL_PRECISION )
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std::cerr << " - Warning: no convergence in function 'integrate', rel. error=" << error/result << std::endl;
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return (real_t)result;
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}
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