#include <mpi.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include "utils.h"
#include "gravity.h"
#include "shortrange-kernel.c"

Include dependency graph for gravity.c:

Macros
#define	NTAB (sizeof(shortrange_force_kernels) / sizeof(shortrange_force_kernels[0]))

Functions
void	gravshort_fill_ntab (const enum ShortRangeForceWindowType ShortRangeForceWindowType, const double Asmth)

int	grav_apply_short_range_window (double r, double fac, double pot, const double cellsize)

Variables
static float	shortrange_table [NTAB]

static float	shortrange_table_potential [NTAB]

static float	shortrange_table_tidal [NTAB]

Macro Definition Documentation

◆ NTAB

#define NTAB (sizeof(shortrange_force_kernels) / sizeof(shortrange_force_kernels[0]))

Definition at line 17 of file gravity.c.

Function Documentation

◆ grav_apply_short_range_window()

int grav_apply_short_range_window	(	double	r,
		double *	fac,
		double *	pot,
		const double	cellsize
	)

Definition at line 55 of file gravity.c.

 {
     const double dx = shortrange_force_kernels[1][0];
     double i = (r / cellsize / dx);
     size_t tabindex = floor(i);
     if(tabindex >= NTAB - 1)
         return 1;
     /* use a linear interpolation; */
     *fac *= (tabindex + 1 - i) * shortrange_table[tabindex] + (i - tabindex) * shortrange_table[tabindex + 1];
     *pot *= (tabindex + 1 - i) * shortrange_table_potential[tabindex] + (i - tabindex) * shortrange_table_potential[tabindex];
     return 0;
 }

References NTAB, shortrange_force_kernels, shortrange_table, and shortrange_table_potential.

Referenced by apply_accn_to_output(), and grav_short_pair_ngbiter().

Here is the caller graph for this function:

◆ gravshort_fill_ntab()

void gravshort_fill_ntab	(	const enum ShortRangeForceWindowType ShortRangeForceWindowType ShortRangeForceWindowType	,
		const double	Asmth
	)

Definition at line 23 of file gravity.c.

 {
     if (ShortRangeForceWindowType == SHORTRANGE_FORCE_WINDOW_TYPE_EXACT) {
         if(Asmth != 1.5) {
             endrun(0, "The short range force window is calibrated for Asmth = 1.5, but running with %g\n", Asmth);
         }
     }
  
     size_t i;
     for(i = 0; i < NTAB; i++)
     {
         /* force_kernels is in units of mesh points; */
         double u = shortrange_force_kernels[i][0] * 0.5 / Asmth;
         switch (ShortRangeForceWindowType) {
             case SHORTRANGE_FORCE_WINDOW_TYPE_EXACT:
                 /* Notice that the table is only calibrated for smth of 1.25*/
                 shortrange_table[i] = shortrange_force_kernels[i][2]; /* ~ erfc(u) + 2.0 * u / sqrt(M_PI) * exp(-u * u); */
                 /* The potential of the calibrated kernel is a bit off, so we still use erfc here; we do not use potential anyways.*/
                 shortrange_table_potential[i] = shortrange_force_kernels[i][1];
             break;
             case SHORTRANGE_FORCE_WINDOW_TYPE_ERFC:
                 shortrange_table[i] = erfc(u) + 2.0 * u / sqrt(M_PI) * exp(-u * u);
                 shortrange_table_potential[i] = erfc(u);
             break;
         }
         /* we don't have a table for that and don't use it anyways. */
         shortrange_table_tidal[i] = 4.0 * u * u * u / sqrt(M_PI) * exp(-u * u);
     }
 }