void comb_filter::ac_processing()
{
double k = 64.0;
double n = 3.0;
sca_complex z = sca_ac_z(1, get_timestep());
sca_complex h;
h = pow((1.0 - pow(z, -k)) / (1.0 - 1.0 / z), n); // comb
sca_ac(outp) = h * sca_ac(inp);
}
/*! This function advances the system in momentum space, i.e. it does apply
* the 'kick' operation after the forces have been computed. Additionally, it
* assigns new timesteps to particles. At start-up, a half-timestep is
* carried out, as well as at the end of the simulation. In between, the
* half-step kick that ends the previous timestep and the half-step kick for
* the new timestep are combined into one operation.
*/
void advance_and_find_timesteps(void)
{
int i, j, no, ti_step, ti_min, tend, tstart;
double dt_entr, dt_entr2, dt_gravkick, dt_hydrokick, dt_gravkick2, dt_hydrokick2, t0, t1;
double minentropy, aphys;
FLOAT dv[3];
#ifdef FLEXSTEPS
int ti_grp;
#endif
#if defined(PSEUDOSYMMETRIC) && !defined(FLEXSTEPS)
double apred, prob;
int ti_step2;
#endif
#ifdef PMGRID
double dt_gravkickA, dt_gravkickB;
#endif
#ifdef MAKEGLASS
double disp, dispmax, globmax, dmean, fac, disp2sum, globdisp2sum;
#endif
t0 = second();
if(All.ComovingIntegrationOn)
{
fac1 = 1 / (All.Time * All.Time);
fac2 = 1 / pow(All.Time, 3 * GAMMA - 2);
fac3 = pow(All.Time, 3 * (1 - GAMMA) / 2.0);
hubble_a = All.Omega0 / (All.Time * All.Time * All.Time)
+ (1 - All.Omega0 - All.OmegaLambda) / (All.Time * All.Time) + All.OmegaLambda;
hubble_a = All.Hubble * sqrt(hubble_a);
a3inv = 1 / (All.Time * All.Time * All.Time);
atime = All.Time;
}
else
fac1 = fac2 = fac3 = hubble_a = a3inv = atime = 1;
#ifdef NOPMSTEPADJUSTMENT
dt_displacement = All.MaxSizeTimestep;
#else
if(Flag_FullStep || dt_displacement == 0)
find_dt_displacement_constraint(hubble_a * atime * atime);
#endif
#ifdef PMGRID
if(All.ComovingIntegrationOn)
dt_gravkickB = get_gravkick_factor(All.PM_Ti_begstep, All.Ti_Current) -
get_gravkick_factor(All.PM_Ti_begstep, (All.PM_Ti_begstep + All.PM_Ti_endstep) / 2);
else
dt_gravkickB = (All.Ti_Current - (All.PM_Ti_begstep + All.PM_Ti_endstep) / 2) * All.Timebase_interval;
if(All.PM_Ti_endstep == All.Ti_Current) /* need to do long-range kick */
{
/* make sure that we reconstruct the domain/tree next time because we don't kick the tree nodes in this case */
All.NumForcesSinceLastDomainDecomp = 1 + All.TotNumPart * All.TreeDomainUpdateFrequency;
}
#endif
#ifdef MAKEGLASS
for(i = 0, dispmax = 0, disp2sum = 0; i < NumPart; i++)
{
for(j = 0; j < 3; j++)
{
P[i].GravPM[j] *= -1;
P[i].GravAccel[j] *= -1;
P[i].GravAccel[j] += P[i].GravPM[j];
P[i].GravPM[j] = 0;
}
disp = sqrt(P[i].GravAccel[0] * P[i].GravAccel[0] +
P[i].GravAccel[1] * P[i].GravAccel[1] + P[i].GravAccel[2] * P[i].GravAccel[2]);
disp *= 2.0 / (3 * All.Hubble * All.Hubble);
disp2sum += disp * disp;
if(disp > dispmax)
dispmax = disp;
}
MPI_Allreduce(&dispmax, &globmax, 1, MPI_DOUBLE, MPI_MAX, MPI_COMM_WORLD);
MPI_Allreduce(&disp2sum, &globdisp2sum, 1, MPI_DOUBLE, MPI_SUM, MPI_COMM_WORLD);
dmean = pow(P[0].Mass / (All.Omega0 * 3 * All.Hubble * All.Hubble / (8 * M_PI * All.G)), 1.0 / 3);
if(globmax > dmean)
fac = dmean / globmax;
else
fac = 1.0;
if(ThisTask == 0)
{
printf("\nglass-making: dmean= %g global disp-maximum= %g rms= %g\n\n",
dmean, globmax, sqrt(globdisp2sum / All.TotNumPart));
fflush(stdout);
}
for(i = 0, dispmax = 0; i < NumPart; i++)
{
for(j = 0; j < 3; j++)
{
P[i].Vel[j] = 0;
P[i].Pos[j] += fac * P[i].GravAccel[j] * 2.0 / (3 * All.Hubble * All.Hubble);
P[i].GravAccel[j] = 0;
}
}
#endif
/* Now assign new timesteps and kick */
#ifdef FLEXSTEPS
if((All.Ti_Current % (4 * All.PresentMinStep)) == 0)
if(All.PresentMinStep < TIMEBASE)
All.PresentMinStep *= 2;
for(i = 0; i < NumPart; i++)
{
if(P[i].Ti_endstep == All.Ti_Current)
{
ti_step = get_timestep(i, &aphys, 0);
/* make it a power 2 subdivision */
ti_min = TIMEBASE;
while(ti_min > ti_step)
ti_min >>= 1;
ti_step = ti_min;
if(ti_step < All.PresentMinStep)
All.PresentMinStep = ti_step;
}
}
