mirror of
https://github.com/cosmo-sims/MUSIC.git
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275753ede2
* Moved hybrid poisson solver from convolution_kernel.cc to poisson.cc * Fine-tuned deconvolution schemes for various running modes * Added lots of doxygen documentation
155 lines
3.3 KiB
C++
155 lines
3.3 KiB
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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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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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-4
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#endif
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int Base_interp::locate(const double x)
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{
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int ju,jm,jl;
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if (n < 2 || mm < 2 || mm > n) throw("locate size error");
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bool ascnd=(xx[n-1] >= xx[0]);
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jl=0;
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ju=n-1;
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while (ju-jl > 1) {
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jm = (ju+jl) >> 1;
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if ((x >= xx[jm]) == ascnd)
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jl=jm;
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else
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ju=jm;
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}
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cor = abs(jl-jsav) > dj ? 0 : 1;
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jsav = jl;
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return std::max(0,std::min(n-mm,jl-((mm-2)>>1)));
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}
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int Base_interp::hunt(const double x)
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{
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int jl=jsav, jm, ju, inc=1;
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if (n < 2 || mm < 2 || mm > n) throw("hunt size error");
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bool ascnd=(xx[n-1] >= xx[0]);
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if (jl < 0 || jl > n-1) {
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jl=0;
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ju=n-1;
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} else {
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if ((x >= xx[jl]) == ascnd) {
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for (;;) {
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ju = jl + inc;
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if (ju >= n-1) {
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ju = n-1;
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break;
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} else if ((x < xx[ju]) == ascnd) break;
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else {
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jl = ju;
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inc += inc;
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}
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}
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} else {
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ju = jl;
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for (;;) {
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jl = jl - inc;
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if (jl <= 0) { jl = 0; break;}
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else if ((x >= xx[jl]) == ascnd) break;
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else {
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ju = jl;
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inc += inc;
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}
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}
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}
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}
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while (ju-jl > 1) {
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jm = (ju+jl) >> 1;
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if ((x >= xx[jm]) == ascnd)
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jl=jm;
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else
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ju=jm;
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}
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cor = abs(jl-jsav) > dj ? 0 : 1;
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jsav = jl;
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return std::max(0,std::min(n-mm,jl-((mm-2)>>1)));
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}
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#if 1
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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;//NULL;
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double result;
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double error;
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//size_t neval;
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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_qng( &F, a, b, 0, REL_PRECISION, &result, &error, &neval );
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//gsl_integration_qags( &F, a, b, 0, REL_PRECISION, 10000, w, &result, &error );
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gsl_integration_workspace_free(w);
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if( error > 10*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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#else
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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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unsigned nn = 1000;
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double la = log10(a), lb = log10(b), dlk = (lb-la)/(nn-1);
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double sum = 0.0;
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for( unsigned i=1; i<nn; ++i )
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{
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double xr = pow(10.0, la+i*dlk );
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double xl = pow(10.0, la+(i-1)*dlk );
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sum += (xr-xl)*func(0.5*(xl+xr),params);
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}
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return sum;
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}
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#endif
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