VlasovAdvection.c File Reference

Contains the function to compute the hyperbolic flux for the Vlasov equations over the domain. More...

#include <math.h>
#include <basic.h>
#include <arrayfunctions.h>
#include <physicalmodels/vlasov.h>
#include <mpivars.h>
#include <hypar.h>

Go to the source code of this file.

Functions
double	VlasovAdvectionCoeff (int *, int, void *)
int	VlasovAdvection (double *f, double *u, int dir, void *s, double t)

Detailed Description

Contains the function to compute the hyperbolic flux for the Vlasov equations over the domain.

Author

John Loffeld

Definition in file VlasovAdvection.c.

Function Documentation

VlasovAdvectionCoeff()

double VlasovAdvectionCoeff	(	int *	idx,
		int	dir,
		void *	s
	)

Returns the advection coefficient at a given grid index \(c\), where

\begin{equation} c = v_i, \end{equation}

if dir < Vlasov::ndims_x ( \(i = {\rm dir}\)), and

\begin{equation} c = E_i, \end{equation}

the electric field if dir >= Vlasov::ndims_x ( \(i = \) dir-Vlasov::ndims_x).

Note: this function assumes that the electric field has already been set.

Parameters

idx	grid index
dir	Spatial dimension
s	Solver object of type HyPar

Definition at line 28 of file VlasovAdvectionCoeff.c.

{

  HyPar  *solver = (HyPar*)  s;
  Vlasov *param  = (Vlasov*) solver->physics;

  int* dim    = solver->dim_local;
  int  ghosts = solver->ghosts;

  double retval = DBL_MAX;

  if (dir < param->ndims_x) {

    int veldim = dir + param->ndims_x;
    _GetCoordinate_(veldim,idx[veldim],dim,ghosts,solver->x,retval);

  }  else {

    int ndims_x = param->ndims_x;
    int dim_x[ndims_x]; _ArrayCopy1D_(dim, dim_x, ndims_x);

    int idx_x[ndims_x];
    _ArrayCopy1D_(idx, idx_x, ndims_x);
    int p; _ArrayIndex1D_(ndims_x, dim_x, idx_x, ghosts, p);
    retval = param->e_field[ndims_x*p+(dir-ndims_x)];
    
  }

  return retval;

}

VlasovAdvection()

int VlasovAdvection	(	double *	f,
		double *	u,
		int	dir,
		void *	s,
		double	t
	)

Compute the hyperbolic flux over the local domain.

\begin{equation} {\bf F}\left({\bf u}(x,v)\right) = c {\bf u}(x,v), \end{equation}

where the advection coefficient \(c\) is computed by VlasovAdvectionCoeff().

Parameters

f	Array to hold the computed flux (same size and layout as u)
u	Array containing the conserved solution
dir	Spatial dimension
s	Solver object of type HyPar
t	Current time

Definition at line 22 of file VlasovAdvection.c.

{

  HyPar  *solver = (HyPar*)  s;
  Vlasov *param  = (Vlasov*) solver->physics;

  int* dim    = solver->dim_local;
  int  ghosts = solver->ghosts;
  int  ndims  = solver->ndims;

  // set bounds for array index to include ghost points
  int bounds[ndims];
  _ArrayCopy1D_(dim,bounds,ndims);
  for (int i=0; i<ndims; i++) bounds[i] += 2*ghosts;

  // set offset such that index is compatible with ghost point arrangement
  int offset[ndims];
  _ArraySetValue_(offset,ndims,-ghosts);

  int done = 0; 
  int index_wog[ndims];
  int index[ndims]; _ArraySetValue_(index,ndims,0);
  while (!done) {

    _ArrayCopy1D_(index, index_wog, ndims);
    for (int i = 0; i < ndims; i++) index_wog[i] -= ghosts;
    double adv_coeff = VlasovAdvectionCoeff(index_wog, dir, solver);

    int p; _ArrayIndex1DWO_(ndims,dim,index,offset,ghosts,p);
    f[p] = adv_coeff * u[p];
    _ArrayIncrementIndex_(ndims,bounds,index,done);

  }

  return 0;
}