func main() {
// PETSc initialization
if err := petsc.Initialize(); err != nil {
petsc.Fatal(err)
}
defer func() {
if err := petsc.Finalize(); err != nil {
petsc.Fatal(err)
}
}()
rank, size := petsc.RankSize()
// Create particles
var np1 int64 = 1
if rank == 0 {
np1 = 2
}
pp, err := structvec.NewStructVec(pstruct{}, np1, petsc.DETERMINE)
if err != nil {
petsc.Fatal(err)
}
defer pp.Destroy()
lpp, _ := pp.GetArray().([]pstruct)
for i := range lpp {
for j := 0; j < 3; j++ {
lpp[i].pos[j] = (float32(i) + 1) * (float32(j + 1 + rank*10))
}
}
pp.RestoreArray()
lpp, _ = pp.GetArray().([]pstruct)
dump(lpp, rank)
pp.RestoreArray()
// Set up scatters
var localndx, mpirank []int64
if rank == 0 {
localndx = make([]int64, 1+size)
mpirank = make([]int64, 1+size)
for i := 0; i < size; i++ {
localndx[i] = 0
mpirank[i] = int64(i)
}
localndx[size] = 1
mpirank[size] = int64((rank + 1) % size)
} else {
localndx = make([]int64, 1)
mpirank = make([]int64, 1)
localndx[0] = 0
mpirank[0] = int64((rank + 1) % size)
}
petsc.Printf("\n\n\n")
pp.Scatter(localndx, mpirank)
lpp, _ = pp.GetArray().([]pstruct)
dump(lpp, rank)
pp.RestoreArray()
}
func main() {
if err := petsc.Initialize(); err != nil {
petsc.Fatal(err)
}
defer func() {
if err := petsc.Finalize(); err != nil {
petsc.Fatal(err)
}
}()
rank, size := petsc.RankSize()
petsc.Printf("Initialization successful\n")
petsc.SyncPrintf("Hello from rank %d of %d\n", rank, size)
petsc.SyncFlush()
}
func NewVec(nlocal, nglobal int64) *structvec.StructVec {
v, err := structvec.NewStructVec(One{}, nlocal, nglobal)
if err != nil {
petsc.Fatal(err)
}
return v
}
// LocalSizeTransposed returns the local size required for the transform,
// as well as the start and end positions for the transposed and untransposed
// dimensions.
//
// Unlike the FFTW3 interface, dims here are the dimensions for the real transform.
//
// returns the local size (number of real elts), n0 and n1 start and local sizes.
func LocalSizeTransposed(dims []int64) (int64, [2]int64, [2]int64) {
ndim := len(dims)
if ndim < 2 {
petsc.Fatal(errors.New("Need at least two dimensions"))
}
rnk := C.int(ndim)
// We're going to change the dimensions, so make a copy.
dims1 := make([]int64, ndim)
copy(dims1, dims)
dims1[ndim-1] = dims[ndim-1]/2 + 1
// ptrdiff_t fftw_mpi_local_size_transposed(int rnk, const ptrdiff_t *n, MPI_Comm comm,
// ptrdiff_t *local_n0, ptrdiff_t *local_0_start,
// ptrdiff_t *local_n1, ptrdiff_t *local_1_start);
var n0, n0start, n1, n1start C.ptrdiff_t
lsize := C.fftw_mpi_local_size_transposed(rnk, (*C.ptrdiff_t)(unsafe.Pointer(&dims1[0])), petsc.WORLD,
&n0, &n0start, &n1, &n1start)
ln0 := [2]int64{int64(n0), int64(n0start)}
ln1 := [2]int64{int64(n1), int64(n1start)}
return int64(lsize) * 2, ln0, ln1
}
// Initialize initializes FFTW3 for MPI usage
func Initialize() {
if C.size_ptrdiff() != 8 {
petsc.Fatal(errors.New("size(ptrdiff_t) != 8"))
}
// Initialize FFTW3
C.fftw_mpi_init()
}
func (s *StructVec) GetArray() interface{} {
if err := s.v.GetArray(); err != nil {
petsc.Fatal(err)
}
// Make sure the lengths match
if int64(len(s.v.Arr)) != (s.Nlocal * s.bs) {
petsc.Fatal(errors.New("Unexpected size of array"))
}
sliceHeaderIn := (*reflect.SliceHeader)(unsafe.Pointer(&s.v.Arr))
ptr := reflect.New(reflect.SliceOf(s.t))
sliceHeaderOut := (*reflect.SliceHeader)(unsafe.Pointer(ptr.Pointer()))
sliceHeaderOut.Cap = int(s.Nlocal)
sliceHeaderOut.Len = int(s.Nlocal)
sliceHeaderOut.Data = sliceHeaderIn.Data
return ptr.Elem().Interface()
}
func main() {
// PETSc initialization
if err := petsc.Initialize(); err != nil {
petsc.Fatal(err)
}
defer func() {
if err := petsc.Finalize(); err != nil {
petsc.Fatal(err)
}
}()
rank, size := petsc.RankSize()
pp := PW3D.NewVec(petsc.DECIDE, 10000)
defer pp.Destroy()
lpp := PW3D.GetArray(pp)
lpp.FillRandom(1, 1)
pp.RestoreArray()
petsc.Printf("Generating random particles....\n")
slab := particles.Slab{L: 1, N: size, Idim: 0}
PW3D.DomainDecompose(slab, pp)
petsc.Printf("Slab decomposition complete\n")
lpp = PW3D.GetArray(pp)
_, mpirank := slab.Domain(lpp)
rank64 := int64(rank)
petsc.SyncPrintf("# Rank %d has %d particles....\n", rank, lpp.Length())
for ipart, irank := range mpirank {
if irank != rank64 {
petsc.SyncPrintf("ERROR: %d expected, %d placed, %+v\n", rank, irank, lpp[ipart])
}
}
petsc.SyncFlush()
pp.RestoreArray()
}
// New returns a new fftw3.Grid of sides dim[] (specified in configuration space)
func New(dims []int64) (greal *Grid, gcmplx *Grid) {
// Check that dims is big enough
ndim := len(dims)
if ndim < 2 {
petsc.Fatal(errors.New("The grid must at least be 2D"))
}
g := new(Grid)
g.dims = make([]int64, ndim)
copy(g.dims, dims)
// Figure out local dimensions
lsize, n0, n1 := LocalSizeTransposed(dims)
// Allocate the real and complex grids
greal = simpleNew(dims, n0, false)
gcmplx = simpleNew(dims, n1, true)
// Ok, now allocate arrays and store the same in both places
_ = lsize
return
}
func main() {
if err := petsc.Initialize(); err != nil {
petsc.Fatal(err)
}
defer func() {
if err := petsc.Finalize(); err != nil {
petsc.Fatal(err)
}
}()
rank, size := petsc.RankSize()
// Create a vector using the local size
v, err := petsc.NewVec(5, petsc.DETERMINE)
if err != nil {
petsc.Fatal(err)
}
n1, err := v.LocalSize()
if err != nil {
petsc.Fatal(err)
}
lo, hi, err := v.OwnRange()
if err != nil {
petsc.Fatal(err)
}
petsc.SyncPrintf("%d rank has local size %d [%d, %d]\n", rank, n1, lo, hi)
petsc.SyncFlush()
err = v.Destroy()
if err != nil {
petsc.Fatal(err)
}
// Create a vector using the global size
v, err = petsc.NewVec(petsc.DECIDE, 100)
if err != nil {
petsc.Fatal(err)
}
n1, err = v.LocalSize()
if err != nil {
petsc.Fatal(err)
}
lo, hi, err = v.OwnRange()
if err != nil {
petsc.Fatal(err)
}
petsc.SyncPrintf("%d rank has local size %d [%d, %d]\n", rank, n1, lo, hi)
petsc.SyncFlush()
// Set and then access the array
if err := v.Set(3.1415926); err != nil {
petsc.Fatal(err)
}
// Try running ownershipranges
if rank == 0 {
rr, err := v.Ranges()
if err != nil {
petsc.Fatal(err)
}
fmt.Println(rr)
if size > 2 {
ix := []int64{rr[1], rr[2], rr[3]}
y := []float64{4.14, 5.14, 6.14}
v.SetValues(ix, y, true)
}
}
v.AssemblyBegin()
v.AssemblyEnd()
if err := v.GetArray(); err != nil {
petsc.Fatal(err)
}
petsc.SyncPrintf("%d rank has local size %d \n", rank, len(v.Arr))
petsc.SyncFlush()
fmt.Println(rank, v.Arr[0:2])
if err := v.RestoreArray(); err != nil {
petsc.Fatal(err)
}
sum, _ := v.Sum()
petsc.Printf("Sum = %f\n", sum)
max, _, _ := v.Max()
petsc.Printf("Max = %f\n", max)
min, _, _ := v.Min()
petsc.Printf("Max = %f\n", min)
v.Scale(0.3)
sum, _ = v.Sum()
petsc.Printf("Sum = %f\n", sum)
err = v.Destroy()
if err != nil {
petsc.Fatal(err)
}
}
func main() {
// PETSc initialization
if err := petsc.Initialize(); err != nil {
petsc.Fatal(err)
}
defer func() {
if err := petsc.Finalize(); err != nil {
petsc.Fatal(err)
}
}()
rank, _ := petsc.RankSize()
v, err := structvec.NewStructVec(pstruct{}, petsc.DECIDE, 10)
if err != nil {
petsc.Fatal(err)
}
defer v.Destroy()
petsc.Printf("Type of v : %s\n", v.Type())
petsc.Printf("Size of v : %d\n", v.BlockSize())
petsc.SyncPrintf("Local size = %d\n", v.Nlocal)
petsc.SyncFlush()
petsc.Printf("Global size = %d\n", v.Ntotal)
// local particle data
lpp, ok := v.GetArray().([]pstruct)
if !ok {
petsc.Fatal(err)
}
for i := range lpp {
lpp[i].FillRandom()
}
err = v.RestoreArray()
if err != nil {
petsc.Fatal(err)
}
// Print array
lpp, ok = v.GetArray().([]pstruct)
if !ok {
petsc.Fatal(err)
}
for i := range lpp {
petsc.SyncPrintf("%s\n", lpp[i])
}
petsc.SyncFlush()
err = v.RestoreArray()
if err != nil {
petsc.Fatal(err)
}
petsc.Printf("----------------\n")
// Fiddle with array
if rank == 0 {
lpp = make([]pstruct, 2)
ix := []int64{3, 7}
err = v.SetValues(ix, lpp)
if err != nil {
petsc.Fatal(err)
}
}
v.AssemblyBegin()
v.AssemblyEnd()
// Print array
lpp, ok = v.GetArray().([]pstruct)
if !ok {
petsc.Fatal(err)
}
for i := range lpp {
petsc.SyncPrintf("%s\n", lpp[i])
}
petsc.SyncFlush()
err = v.RestoreArray()
if err != nil {
petsc.Fatal(err)
}
}
// Scatter takes the particles and reshuffles them across MPI ranks according to localid and
//
// localid is the local index of the particle, while mpirank is the destination rank for the particle.
// Note that this is completely general, and a particle may be shunted to many ranks (useful for ghosts).
// Also, note that localndx and mpirank will be modified by this routine.
//
func (s *StructVec) Scatter(localndx, mpirank []int64) {
// Get the rank and size
rank, size := petsc.RankSize()
// Work out the final number of particles
var npart_local, npart_final int64
npart_local = int64(len(mpirank))
mpi.AllReduceInt64(petsc.WORLD, &npart_local, &npart_final, 1, mpi.SUM)
//petsc.Printf("%d total particles expected after scatter\n", npart_final)
// Allocate arrays
// narr[rank] are the number of particles headed for rank from the current rank (hereafter crank)
// narr1[crank*size + rank] collects all the narr's, allowing every processor to know what index it needs to send objects to.
// icount keeps track of indices that objects need to go to.
// icount_check is used for assertion tests, to make sure nothing bad happened.
narr := make([]int64, size)
icount := make([]int64, size)
narr1 := make([]int64, size*size)
icount_check := make([]int64, size)
// Loop over mpirank, incrementing narr
for _, irank := range mpirank {
narr[irank] += 1
}
mpi.AllGatherInt64(petsc.WORLD, narr, narr1)
//petsc.Printf("%v\n", narr1)
// Reset narr, icount
for i := range narr {
narr[i] = 0
icount[i] = 0
}
for i := 0; i < size; i++ {
// narr now holds the total number of local particles
for j := 0; j < size; j++ {
narr[i] += narr1[i+j*size]
}
// icount now holds the number of particles from ranks before my rank, on rank i
for j := 0; j < rank; j++ {
icount[i] += narr1[i+j*size]
}
}
// Now switch icount to global indices
// icount_check is the expected final global index
rtot := int64(0)
for i := 0; i < size; i++ {
icount[i] += rtot
rtot += narr[i]
icount_check[i] = icount[i] + narr1[i+rank*size]
}
// Assertion check
if rtot != npart_final {
petsc.Fatal(errors.New("ASSERTION FAILURE : rtot != npart_final"))
}
// Now we start updating localndx and mpirank
lo, _, _ := s.OwnRange()
irank := int64(0)
for i := range mpirank {
localndx[i] += lo
irank = mpirank[i]
mpirank[i] = icount[irank]
icount[irank]++
}
// Assertion check
for i := range icount {
if icount[i] != icount_check[i] {
petsc.Fatal(errors.New("ASSERTION FAILURE : icount != icount_check"))
}
}
// Create destination
vecnew, err := petsc.NewVecBlocked(narr[rank]*s.bs, petsc.DETERMINE, s.bs)
if err != nil {
petsc.Fatal(err)
}
// Create index sets
isin, err := petsc.NewBlockedIS(s.bs, npart_local, localndx)
if err != nil {
petsc.Fatal(err)
}
isout, err := petsc.NewBlockedIS(s.bs, npart_local, mpirank)
if err != nil {
petsc.Fatal(err)
}
defer isin.Destroy()
defer isout.Destroy()
// Create scatter context
ctx, err := petsc.NewScatter(s.v, vecnew, isin, isout)
defer ctx.Destroy()
ctx.Begin(s.v, vecnew, false, true)
ctx.End(s.v, vecnew, false, true)
// Clean up
s.v.Destroy()
s.v = vecnew
s.Nlocal = narr[rank]
s.Ntotal = npart_final
}