void
fastpm_png_induce_correlation(FastPMPNGaussian * png, PM * pm, FastPMFloat * delta_k)
{
FastPMFloat * g_x = pm_alloc(pm);
png->Volume = pm->Volume;
fastpm_ic_induce_correlation(pm, delta_k, (fastpm_fkfunc) fastpm_png_potential, png);
pm_assign(pm, delta_k, g_x);
pm_c2r(pm, g_x);
fastpm_png_transform_potential(pm, g_x, png);
pm_r2c(pm, g_x, delta_k);
pm_free(pm, g_x);
fastpm_apply_any_transfer(pm, delta_k, delta_k, (fastpm_fkfunc) fastpm_png_transfer_function, png);
}
void
fastpm_calculate_forces(FastPM * fastpm, FastPMFloat * delta_k)
{
PMStore * p = fastpm->base.p;
PM * pm = fastpm->base.pm;
FastPMPainter reader[1];
fastpm_painter_init(reader, pm, FASTPM_PAINTER_CIC, 1);
/* watch out: boost the density since mesh is finer than grid */
double density_factor = pm->Norm / pow(1.0 * fastpm->nc, 3);
CLOCK(ghosts);
PMGhostData * pgd = pm_ghosts_create(pm, p, PACK_POS, NULL);
LEAVE(ghosts);
FastPMFloat * canvas = pm_alloc(pm);
/* Watch out: this paints number of particles per cell. when pm_nc_factor is not 1,
* it is less than the density (a cell is smaller than the mean seperation between particles.
* We thus have to boost the density by density_factor.
* */
CLOCK(paint);
fastpm_paint_store(fastpm->painter, canvas,
p, p->np + pgd->nghosts, NULL, 0);
fastpm_apply_multiply_transfer(pm, canvas, canvas, density_factor);
LEAVE(paint);
CLOCK(r2c);
pm_r2c(pm, canvas, delta_k);
LEAVE(r2c);
/* calculate the forces save them to p->acc */
switch(fastpm->DEALIASING_TYPE) {
case FASTPM_DEALIASING_TWO_THIRD:
{
double k_nq = M_PI / pm->BoxSize[0] * pm->Nmesh[0];
fastpm_apply_lowpass_transfer(pm, delta_k, delta_k, 2.0 / 3 * k_nq);
}
break;
case FASTPM_DEALIASING_GAUSSIAN:
apply_gaussian_dealiasing(pm, delta_k, delta_k, 1.0);
break;
case FASTPM_DEALIASING_AGGRESSIVE_GAUSSIAN:
apply_gaussian_dealiasing(pm, delta_k, delta_k, 4.0);
break;
case FASTPM_DEALIASING_GAUSSIAN36:
{
double k_nq = M_PI / pm->BoxSize[0] * pm->Nmesh[0];
fastpm_apply_any_transfer(pm, delta_k, delta_k, (fastpm_fkfunc) gaussian36, &k_nq);
}
break;
case FASTPM_DEALIASING_NONE:
break;
default:
fastpm_raise(-1, "wrong dealiasing kernel type");
}
int d;
int ACC[] = {PACK_ACC_X, PACK_ACC_Y, PACK_ACC_Z};
for(d = 0; d < 3; d ++) {
CLOCK(transfer);
switch(fastpm->KERNEL_TYPE) {
case FASTPM_KERNEL_EASTWOOD:
apply_force_kernel_eastwood(pm, delta_k, canvas, d, 1);
break;
case FASTPM_KERNEL_NAIVE:
apply_force_kernel_eastwood(pm, delta_k, canvas, d, 0);
break;
case FASTPM_KERNEL_GADGET:
apply_force_kernel_gadget(pm, delta_k, canvas, d, 1);
break;
case FASTPM_KERNEL_3_4:
apply_force_kernel(pm, delta_k, canvas, d);
break;
case FASTPM_KERNEL_5_4:
apply_force_kernel_5_4(pm, delta_k, canvas, d);
break;
case FASTPM_KERNEL_3_2:
apply_force_kernel_3_2(pm, delta_k, canvas, d);
break;
default:
fastpm_raise(-1, "Wrong kernel type\n");
}
LEAVE(transfer);
CLOCK(c2r);
pm_c2r(pm, canvas);
LEAVE(c2r);
CLOCK(readout);
fastpm_readout_store(reader, canvas, p, p->np + pgd->nghosts, NULL, ACC[d]);
LEAVE(readout);
CLOCK(reduce);
pm_ghosts_reduce(pgd, ACC[d]);
LEAVE(reduce);
}
pm_free(pm, canvas);
pm_ghosts_free(pgd);
}
