/*
Given a DA generates a VecScatter context that will deliver a slice
of the global vector to each processor. In this example, each processor
receives the values i=*, j=*, k=rank, i.e. one z plane.
Note: This code is written assuming only one degree of freedom per node.
For multiple degrees of freedom per node use ISCreateBlock()
instead of ISCreateGeneral().
*/
PetscErrorCode GenerateSliceScatter(DA da,VecScatter *scatter,Vec *vslice)
{
AO ao;
PetscInt M,N,P,nslice,*sliceindices,count,i,j;
PetscMPIInt rank;
PetscErrorCode ierr;
MPI_Comm comm;
Vec vglobal;
IS isfrom,isto;
ierr = PetscObjectGetComm((PetscObject)da,&comm);CHKERRQ(ierr);
ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
ierr = DAGetAO(da,&ao);CHKERRQ(ierr);
ierr = DAGetInfo(da,0,&M,&N,&P,0,0,0,0,0,0,0);CHKERRQ(ierr);
/*
nslice is number of degrees of freedom in this processors slice
if there are more processors then z plans the extra processors get 0
elements in their slice.
*/
if (rank < P) {nslice = M*N;} else nslice = 0;
/*
Generate the local vector to hold this processors slice
*/
ierr = VecCreateSeq(PETSC_COMM_SELF,nslice,vslice);CHKERRQ(ierr);
ierr = DACreateGlobalVector(da,&vglobal);CHKERRQ(ierr);
/*
Generate the indices for the slice in the "natural" global ordering
Note: this is just an example, one could select any subset of nodes
on each processor. Just list them in the global natural ordering.
*/
ierr = PetscMalloc((nslice+1)*sizeof(PetscInt),&sliceindices);CHKERRQ(ierr);
count = 0;
if (rank < P) {
for (j=0; j<N; j++) {
for (i=0; i<M; i++) {
sliceindices[count++] = rank*M*N + j*M + i;
}
}
}
/*
Convert the indices to the "PETSc" global ordering
*/
ierr = AOApplicationToPetsc(ao,nslice,sliceindices);CHKERRQ(ierr);
/* Create the "from" and "to" index set */
/* This is to scatter from the global vector */
ierr = ISCreateGeneral(PETSC_COMM_SELF,nslice,sliceindices,&isfrom);CHKERRQ(ierr);
/* This is to gather into the local vector */
ierr = ISCreateStride(PETSC_COMM_SELF,nslice,0,1,&isto);CHKERRQ(ierr);
ierr = VecScatterCreate(vglobal,isfrom,*vslice,isto,scatter);CHKERRQ(ierr);
ierr = ISDestroy(isfrom);CHKERRQ(ierr);
ierr = ISDestroy(isto);CHKERRQ(ierr);
ierr = PetscFree(sliceindices);CHKERRQ(ierr);
return 0;
}
PetscErrorCode vizGA2DA()
{
PetscErrorCode ierr;
int rank;
MPI_Comm_rank(PETSC_COMM_WORLD,&rank);
int d1 = 40, d2 = 50;
DA da;
Vec vec;
const PetscInt *lx, *ly, *lz;
PetscInt m,n,p;
DALocalInfo info;
ierr = DACreate2d(PETSC_COMM_WORLD,DA_NONPERIODIC,DA_STENCIL_STAR,
d1,d2,PETSC_DECIDE,PETSC_DECIDE,1,1,0,0, &da); CHKERRQ(ierr);
ierr = DACreateGlobalVector(da, &vec); CHKERRQ(ierr);
ierr = DAGetOwnershipRanges(da, &lx, &ly, &lz); CHKERRQ(ierr);
ierr = DAGetLocalInfo(da,&info); CHKERRQ(ierr);
ierr = DAGetInfo(da,0,0,0,0,&m,&n,&p,0,0,0,0); CHKERRQ(ierr);
/**/
ierr = DAView(da, PETSC_VIEWER_STDOUT_WORLD); CHKERRQ(ierr);
for (int i = 0; i < m; ++i) {
PetscPrintf(PETSC_COMM_WORLD,"%d\tlx: %d\n",i,lx[i]);
}
for (int i = 0; i < n; ++i) {
PetscPrintf(PETSC_COMM_WORLD,"%d\tly: %d\n",i,ly[i]);
}
/**/
int ga = GA_Create_handle();
int ndim = 2;
int dims[2] = {d2,d1};
GA_Set_data(ga,2,dims,MT_DBL);
int *map;
PetscMalloc( sizeof(int)*(m+n), &map);
map[0] = 0;
for( int i = 1; i < n; i++ )
{
map[i] = ly[i-1] + map[i-1];
}
map[n] = 0;
for( int i = n+1; i < m+n; i++ )
{
map[i] = lx[i-n-1] + map[i-1];
}
/* correct ordering, but nodeid's dont line up with mpi rank for petsc's da
* DA: +---+---+ GA: +---+---+
* +-2-+-3-+ +-1-+-3-+
* +---+---+ +---+---+
* +-0-+-1-+ +-0-+-2-+
* +---+---+ +---+---+
int *map;
PetscMalloc( sizeof(int)*(m+n), &map);
map[0] = 0;
for( int i = 1; i < m; i++ )
{
map[i] = lx[i] + map[i-1];
}
map[m] = 0;
for( int i = m+1; i < m+n; i++ )
{
map[i] = ly[i-m] + map[i-1];
}
*/
int block[2] = {n,m};
GA_Set_irreg_distr(ga,map,block);
ierr = GA_Allocate( ga );
if( !ierr ) GA_Error("\n\n\nga allocaltion failed\n\n",ierr);
if( !ga ) GA_Error("\n\n\n ga null \n\n",ierr);
if( rank != GA_Nodeid() ) GA_Error("MPI rank does not match GA_Nodeid()",1);
GA_Print_distribution(ga);
int lo[2], hi[2];
NGA_Distribution(ga,rank,lo,hi);
if( lo[1] != info.xs || hi[1] != info.xs+info.xm-1 ||
lo[0] != info.ys || hi[0] != info.ys+info.ym-1 )
{
PetscSynchronizedPrintf(PETSC_COMM_SELF,"[%d] lo:(%2d,%2d) hi:(%2d,%2d) \t DA: (%2d,%2d), (%2d, %2d)\n",
rank, lo[1], lo[0], hi[1], hi[0], info.xs, info.ys, info.xs+info.xm-1, info.ys+info.ym-1);
}
PetscBarrier(0);
PetscSynchronizedFlush(PETSC_COMM_WORLD);
AO ao;
DAGetAO(da,&ao);
if( rank == 0 )
{
int *idx, len = d1*d2;
PetscReal *val;
PetscMalloc(sizeof(PetscReal)*len, &val);
PetscMalloc(sizeof(int)*len, &idx);
for (int j = 0; j < d2; ++j)
{
for (int i = 0; i < d1; ++i)
{
idx[i + d1*j] = i + d1*j;
val[i + d1*j] = i + d1*j;
}
}
AOApplicationToPetsc(ao,len,idx);
VecSetValues(vec,len,idx,val,INSERT_VALUES);
int a[2], b[2],ld[1]={0};
double c = 0;
for (int j = 0; j < d2; ++j)
{
for (int i = 0; i < d1; ++i)
{
a[0] = j;
a[1] = i;
// printf("%5.0f ",c);
NGA_Put(ga,a,a,&c,ld);
c++;
}
}
}
// GA_Print(ga);
VecAssemblyBegin(vec);
VecAssemblyEnd(vec);
int ld;
double *ptr;
NGA_Access(ga,lo,hi,&ptr,&ld);
PetscReal **d;
int c=0;
ierr = DAVecGetArray(da,vec,&d); CHKERRQ(ierr);
for (int j = info.ys; j < info.ys+info.ym; ++j)
{
for (int i = info.xs; i < info.xs+info.xm; ++i)
{
if( d[j][i] != ptr[(i-info.xs)+ld*(j-info.ys)] )
GA_Error("DA array is not equal to GA array",1);
// printf("%d (%d,%d):\t%3.0f\t%3.0f\n", c, i, j, d[j][i], ptr[(i-info.xs)+ld*(j-info.ys)]);
c++;
}
}
ierr = DAVecRestoreArray(da,vec,&d); CHKERRQ(ierr);
c=0;
PetscReal *v;
int start, end;
VecGetOwnershipRange(vec, &start, &end);
VecGetArray( vec, &v );
for( int i = start; i < end; i++)
{
// printf("%d:\t%3.0f\t%3.0f\t%s\n", start, v[i-start], ptr[i-start], (v[i-start]-ptr[i-start]==0?"":"NO") );
}
VecRestoreArray( vec, &v );
NGA_Release_update(ga,lo,hi);
Vec gada;
VecCreateMPIWithArray(((PetscObject)da)->comm,da->Nlocal,PETSC_DETERMINE,ptr,&gada);
VecView(gada,PETSC_VIEWER_STDOUT_SELF);
GA_Destroy(ga);
ierr = VecDestroy(vec); CHKERRQ(ierr);
ierr = DADestroy(da); CHKERRQ(ierr);
PetscFunctionReturn(0);
}