hypre_SStructPMatrix *
hypre_SysPFMGCreateInterpOp( hypre_SStructPMatrix *A,
hypre_SStructPGrid *cgrid,
HYPRE_Int cdir )
{
hypre_SStructPMatrix *P;
hypre_Index *stencil_shape;
HYPRE_Int stencil_size;
HYPRE_Int ndim;
HYPRE_Int nvars;
hypre_SStructStencil **P_stencils;
HYPRE_Int i,s;
/* set up stencil_shape */
stencil_size = 2;
stencil_shape = hypre_CTAlloc(hypre_Index, stencil_size);
for (i = 0; i < stencil_size; i++)
{
hypre_SetIndex3(stencil_shape[i], 0, 0, 0);
}
hypre_IndexD(stencil_shape[0], cdir) = -1;
hypre_IndexD(stencil_shape[1], cdir) = 1;
/* set up P_stencils */
ndim = hypre_StructStencilNDim(hypre_SStructPMatrixSStencil(A, 0, 0));
nvars = hypre_SStructPMatrixNVars(A);
P_stencils = hypre_CTAlloc(hypre_SStructStencil *, nvars);
for (s = 0; s < nvars; s++)
{
HYPRE_SStructStencilCreate(ndim, stencil_size, &P_stencils[s]);
for (i = 0; i < stencil_size; i++)
{
HYPRE_SStructStencilSetEntry(P_stencils[s], i,
stencil_shape[i], s);
}
}
/* create interpolation matrix */
hypre_SStructPMatrixCreate(hypre_SStructPMatrixComm(A), cgrid,
P_stencils, &P);
hypre_TFree(stencil_shape);
return P;
}
hypre_SStructPMatrix *
hypre_SysPFMGCreateRAPOp( hypre_SStructPMatrix *R,
hypre_SStructPMatrix *A,
hypre_SStructPMatrix *P,
hypre_SStructPGrid *coarse_grid,
HYPRE_Int cdir )
{
hypre_SStructPMatrix *RAP;
HYPRE_Int ndim;
HYPRE_Int nvars;
hypre_SStructVariable vartype;
hypre_SStructStencil **RAP_stencils;
hypre_StructMatrix *RAP_s;
hypre_StructMatrix *R_s;
hypre_StructMatrix *A_s;
hypre_StructMatrix *P_s;
hypre_Index **RAP_shapes;
hypre_StructStencil *sstencil;
hypre_Index *shape;
HYPRE_Int s;
HYPRE_Int *sstencil_sizes;
HYPRE_Int stencil_size;
hypre_StructGrid *cgrid;
HYPRE_Int vi,vj;
HYPRE_Int sten_cntr;
HYPRE_Int P_stored_as_transpose = 0;
ndim = hypre_StructStencilDim(hypre_SStructPMatrixSStencil(A, 0, 0));
nvars = hypre_SStructPMatrixNVars(A);
vartype = hypre_SStructPGridVarType(coarse_grid, 0);
cgrid = hypre_SStructPGridVTSGrid(coarse_grid, vartype);
RAP_stencils = hypre_CTAlloc(hypre_SStructStencil *, nvars);
RAP_shapes = hypre_CTAlloc(hypre_Index *, nvars);
sstencil_sizes = hypre_CTAlloc(HYPRE_Int, nvars);
/*--------------------------------------------------------------------------
* Symmetry within a block is exploited, but not symmetry of the form
* A_{vi,vj} = A_{vj,vi}^T.
*--------------------------------------------------------------------------*/
for (vi = 0; vi < nvars; vi++)
{
R_s = hypre_SStructPMatrixSMatrix(R, vi, vi);
stencil_size = 0;
for (vj = 0; vj < nvars; vj++)
{
A_s = hypre_SStructPMatrixSMatrix(A, vi, vj);
P_s = hypre_SStructPMatrixSMatrix(P, vj, vj);
sstencil_sizes[vj] = 0;
if (A_s != NULL)
{
RAP_s = hypre_SemiCreateRAPOp(R_s, A_s, P_s,
cgrid, cdir,
P_stored_as_transpose);
/* Just want stencil for RAP */
hypre_StructMatrixInitializeShell(RAP_s);
sstencil = hypre_StructMatrixStencil(RAP_s);
shape = hypre_StructStencilShape(sstencil);
sstencil_sizes[vj] = hypre_StructStencilSize(sstencil);
stencil_size += sstencil_sizes[vj];
RAP_shapes[vj] = hypre_CTAlloc(hypre_Index,
sstencil_sizes[vj]);
for (s = 0; s < sstencil_sizes[vj]; s++)
{
hypre_CopyIndex(shape[s],RAP_shapes[vj][s]);
}
hypre_StructMatrixDestroy(RAP_s);
}
}
HYPRE_SStructStencilCreate(ndim, stencil_size, &RAP_stencils[vi]);
sten_cntr = 0;
for (vj = 0; vj < nvars; vj++)
{
if (sstencil_sizes[vj] > 0)
{
for (s = 0; s < sstencil_sizes[vj]; s++)
{
HYPRE_SStructStencilSetEntry(RAP_stencils[vi],
sten_cntr, RAP_shapes[vj][s], vj);
sten_cntr++;
}
hypre_TFree(RAP_shapes[vj]);
}
}
}
/* create RAP Pmatrix */
hypre_SStructPMatrixCreate(hypre_SStructPMatrixComm(A),
coarse_grid, RAP_stencils, &RAP);
hypre_TFree(RAP_shapes);
hypre_TFree(sstencil_sizes);
return RAP;
}
