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Gear/src/longrange.c
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longrange.c
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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <mpi.h>
#include "allvars.h"
#include "proto.h"
/*! \file longrange.c
* \brief driver routines for computation of long-range gravitational PM force
*/
#ifdef PMGRID
/*! Calls initializiation routines of periodic or/and non-periodic FFT
* routines.
*/
void long_range_init(void)
{
#ifdef PERIODIC
pm_init_periodic();
#ifdef PLACEHIGHRESREGION
pm_init_nonperiodic();
#endif
#else
pm_init_nonperiodic();
#endif
}
/*! This function calls subroutines that determine the spatial region covered
* by the PM mesh.
*/
void long_range_init_regionsize(void)
{
#ifdef PERIODIC
#ifdef PLACEHIGHRESREGION
if(RestartFlag != 1)
pm_init_regionsize();
pm_setup_nonperiodic_kernel();
#endif
#else
if(RestartFlag != 1)
pm_init_regionsize();
pm_setup_nonperiodic_kernel();
#endif
}
/*! This function is a driver routine for the long-range PM force
* computation. It calls periodic and/or non-periodic FFT routines as needed
* for the present simulation set-up.
*/
void long_range_force(void)
{
int i;
#ifndef PERIODIC
int j;
double fac;
#endif
for(i = 0; i < NumPart; i++)
P[i].GravPM[0] = P[i].GravPM[1] = P[i].GravPM[2] = 0;
#ifdef NOGRAVITY
return;
#endif
#ifdef PERIODIC
pmforce_periodic();
#ifdef PLACEHIGHRESREGION
i = pmforce_nonperiodic(1);
if(i == 1) /* this is returned if a particle lied outside allowed range */
{
pm_init_regionsize();
pm_setup_nonperiodic_kernel();
i = pmforce_nonperiodic(1); /* try again */
}
if(i == 1)
endrun(68686);
#endif
#else
i = pmforce_nonperiodic(0);
if(i == 1) /* this is returned if a particle lied outside allowed range */
{
pm_init_regionsize();
pm_setup_nonperiodic_kernel();
i = pmforce_nonperiodic(0); /* try again */
}
if(i == 1)
endrun(68687);
#ifdef PLACEHIGHRESREGION
i = pmforce_nonperiodic(1);
if(i == 1) /* this is returned if a particle lied outside allowed range */
{
pm_init_regionsize();
pm_setup_nonperiodic_kernel();
/* try again */
for(i = 0; i < NumPart; i++)
P[i].GravPM[0] = P[i].GravPM[1] = P[i].GravPM[2] = 0;
i = pmforce_nonperiodic(0) + pmforce_nonperiodic(1);
}
if(i != 0)
endrun(68688);
#endif
#endif
#ifndef PERIODIC
if(All.ComovingIntegrationOn)
{
fac = 0.5 * All.Hubble * All.Hubble * All.Omega0;
for(i = 0; i < NumPart; i++)
for(j = 0; j < 3; j++)
P[i].GravPM[j] += fac * P[i].Pos[j];
}
/* Finally, the following factor allows a computation of cosmological simulation
with vacuum energy in physical coordinates */
if(All.ComovingIntegrationOn == 0)
{
fac = All.OmegaLambda * All.Hubble * All.Hubble;
for(i = 0; i < NumPart; i++)
for(j = 0; j < 3; j++)
P[i].GravPM[j] += fac * P[i].Pos[j];
}
#endif
}
#endif
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