/*@
DMDAGetReducedDMDA - Gets the DMDA with the same layout but with fewer or more fields
Collective on DMDA
Input Parameters:
+ da - the distributed array
- nfields - number of fields in new DMDA
Output Parameter:
. nda - the new DMDA
Level: intermediate
.keywords: distributed array, get, corners, nodes, local indices, coordinates
.seealso: DMDAGetGhostCorners(), DMSetCoordinates(), DMDASetUniformCoordinates(), DMGetCoordinates(), DMDAGetGhostedCoordinates()
@*/
PetscErrorCode DMDAGetReducedDMDA(DM da,PetscInt nfields,DM *nda)
{
PetscErrorCode ierr;
DM_DA *dd = (DM_DA*)da->data;
PetscInt s,m,n,p,M,N,P,dim,Mo,No,Po;
const PetscInt *lx,*ly,*lz;
DMBoundaryType bx,by,bz;
DMDAStencilType stencil_type;
PetscInt ox,oy,oz;
PetscInt cl,rl;
PetscFunctionBegin;
dim = da->dim;
M = dd->M;
N = dd->N;
P = dd->P;
m = dd->m;
n = dd->n;
p = dd->p;
s = dd->s;
bx = dd->bx;
by = dd->by;
bz = dd->bz;
stencil_type = dd->stencil_type;
ierr = DMDAGetOwnershipRanges(da,&lx,&ly,&lz);CHKERRQ(ierr);
if (dim == 1) {
ierr = DMDACreate1d(PetscObjectComm((PetscObject)da),bx,M,nfields,s,dd->lx,nda);CHKERRQ(ierr);
} else if (dim == 2) {
ierr = DMDACreate2d(PetscObjectComm((PetscObject)da),bx,by,stencil_type,M,N,m,n,nfields,s,lx,ly,nda);CHKERRQ(ierr);
} else if (dim == 3) {
ierr = DMDACreate3d(PetscObjectComm((PetscObject)da),bx,by,bz,stencil_type,M,N,P,m,n,p,nfields,s,lx,ly,lz,nda);CHKERRQ(ierr);
}
ierr = DMSetUp(*nda);CHKERRQ(ierr);
if (da->coordinates) {
ierr = PetscObjectReference((PetscObject)da->coordinates);CHKERRQ(ierr);
(*nda)->coordinates = da->coordinates;
}
/* allow for getting a reduced DA corresponding to a domain decomposition */
ierr = DMDAGetOffset(da,&ox,&oy,&oz,&Mo,&No,&Po);CHKERRQ(ierr);
ierr = DMDASetOffset(*nda,ox,oy,oz,Mo,No,Po);CHKERRQ(ierr);
/* allow for getting a reduced DA corresponding to a coarsened DA */
ierr = DMGetCoarsenLevel(da,&cl);CHKERRQ(ierr);
ierr = DMGetRefineLevel(da,&rl);CHKERRQ(ierr);
(*nda)->levelup = rl;
(*nda)->leveldown = cl;
PetscFunctionReturn(0);
}
PETSC_EXTERN void PETSC_STDCALL dmdagetoffset_(DM da,PetscInt *xo,PetscInt *yo,PetscInt *zo,PetscInt *Mo,PetscInt *No,PetscInt *Po, int *__ierr ){
*__ierr = DMDAGetOffset(
(DM)PetscToPointer((da) ),xo,yo,zo,Mo,No,Po);
}
/*@
DMDACreatePatchIS - Creates an index set corresponding to a patch of the DA.
Not Collective
Input Parameters:
+ da - the DMDA
. lower - a matstencil with i, j and k corresponding to the lower corner of the patch
- upper - a matstencil with i, j and k corresponding to the upper corner of the patch
Output Parameters:
. is - the IS corresponding to the patch
Level: developer
.seealso: DMDACreateDomainDecomposition(), DMDACreateDomainDecompositionScatters()
@*/
PetscErrorCode DMDACreatePatchIS(DM da,MatStencil *lower,MatStencil *upper,IS *is)
{
PetscInt ms=0,ns=0,ps=0;
PetscInt me=1,ne=1,pe=1;
PetscInt mr=0,nr=0,pr=0;
PetscInt ii,jj,kk;
PetscInt si,sj,sk;
PetscInt i,j,k,l,idx;
PetscInt base;
PetscInt xm=1,ym=1,zm=1;
const PetscInt *lx,*ly,*lz;
PetscInt ox,oy,oz;
PetscInt m,n,p,M,N,P,dof;
PetscInt nindices;
PetscInt *indices;
DM_DA *dd = (DM_DA*)da->data;
PetscErrorCode ierr;
PetscFunctionBegin;
/* need to get the sizes of the actual DM rather than the "global" space of a subdomain DM */
M = dd->M;N = dd->N;P=dd->P;
m = dd->m;n = dd->n;p=dd->p;
dof = dd->w;
ierr = DMDAGetOffset(da,&ox,&oy,&oz,NULL,NULL,NULL);CHKERRQ(ierr);
ierr = DMDAGetOwnershipRanges(da,&lx,&ly,&lz);CHKERRQ(ierr);
nindices = (upper->i - lower->i)*(upper->j - lower->j)*(upper->k - lower->k)*dof;
ierr = PetscMalloc(sizeof(PetscInt)*nindices,&indices);CHKERRQ(ierr);
/* start at index 0 on processor 0 */
mr = 0;
nr = 0;
pr = 0;
ms = 0;
ns = 0;
ps = 0;
if (lx) me = lx[0];
if (ly) ne = ly[0];
if (lz) pe = lz[0];
idx = 0;
for (k=lower->k-oz;k<upper->k-oz;k++) {
for (j=lower->j-oy;j < upper->j-oy;j++) {
for (i=lower->i-ox;i < upper->i-ox;i++) {
/* "actual" indices rather than ones outside of the domain */
ii = i;
jj = j;
kk = k;
if (ii < 0) ii = M + ii;
if (jj < 0) jj = N + jj;
if (kk < 0) kk = P + kk;
if (ii > M-1) ii = ii - M;
if (jj > N-1) jj = jj - N;
if (kk > P-1) kk = kk - P;
/* gone out of processor range on x axis */
while(ii > me-1 || ii < ms) {
if (mr == m-1) {
ms = 0;
me = lx[0];
mr = 0;
} else {
mr++;
ms = me;
me += lx[mr];
}
}
/* gone out of processor range on y axis */
while(jj > ne-1 || jj < ns) {
if (nr == n-1) {
ns = 0;
ne = ly[0];
nr = 0;
} else {
nr++;
ns = ne;
ne += ly[nr];
}
}
/* gone out of processor range on z axis */
while(kk > pe-1 || kk < ps) {
if (pr == p-1) {
ps = 0;
pe = lz[0];
pr = 0;
} else {
pr++;
ps = pe;
pe += lz[pr];
}
}
/* compute the vector base on owning processor */
xm = me - ms;
ym = ne - ns;
zm = pe - ps;
base = ms*ym*zm + ns*M*zm + ps*M*N;
/* compute the local coordinates on owning processor */
si = ii - ms;
sj = jj - ns;
sk = kk - ps;
for (l=0;l<dof;l++) {
indices[idx] = l + dof*(base + si + xm*sj + xm*ym*sk);
idx++;
}
}
}
}
ISCreateGeneral(PETSC_COMM_SELF,idx,indices,PETSC_OWN_POINTER,is);CHKERRQ(ierr);
PetscFunctionReturn(0);
}
