1 2 static char help[] = "Scatters from a parallel vector to a sequential vector.\n\ 3 Tests where the local part of the scatter is a copy.\n\n"; 4 5 #include <petscvec.h> 6 7 int main(int argc,char **argv) 8 { 9 PetscMPIInt size,rank; 10 PetscInt n = 5,i,*blks,bs = 1,m = 2; 11 PetscScalar value; 12 Vec x,y; 13 IS is1,is2; 14 VecScatter ctx = 0; 15 PetscViewer sviewer; 16 17 PetscCall(PetscInitialize(&argc,&argv,(char*)0,help)); 18 19 PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL)); 20 PetscCall(PetscOptionsGetInt(NULL,NULL,"-bs",&bs,NULL)); 21 22 PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size)); 23 PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD,&rank)); 24 25 /* create two vectors */ 26 PetscCall(VecCreate(PETSC_COMM_WORLD,&x)); 27 PetscCall(VecSetSizes(x,PETSC_DECIDE,size*bs*n)); 28 PetscCall(VecSetFromOptions(x)); 29 30 /* create two index sets */ 31 if (rank < size-1) m = n + 2; 32 else m = n; 33 34 PetscCall(PetscMalloc1(m,&blks)); 35 blks[0] = n*rank; 36 for (i=1; i<m; i++) blks[i] = blks[i-1] + 1; 37 PetscCall(ISCreateBlock(PETSC_COMM_SELF,bs,m,blks,PETSC_COPY_VALUES,&is1)); 38 PetscCall(PetscFree(blks)); 39 40 PetscCall(VecCreateSeq(PETSC_COMM_SELF,bs*m,&y)); 41 PetscCall(ISCreateStride(PETSC_COMM_SELF,bs*m,0,1,&is2)); 42 43 /* each processor inserts the entire vector */ 44 /* this is redundant but tests assembly */ 45 for (i=0; i<bs*n*size; i++) { 46 value = (PetscScalar) i; 47 PetscCall(VecSetValues(x,1,&i,&value,INSERT_VALUES)); 48 } 49 PetscCall(VecAssemblyBegin(x)); 50 PetscCall(VecAssemblyEnd(x)); 51 PetscCall(VecView(x,PETSC_VIEWER_STDOUT_WORLD)); 52 53 PetscCall(VecScatterCreate(x,is1,y,is2,&ctx)); 54 PetscCall(VecScatterBegin(ctx,x,y,INSERT_VALUES,SCATTER_FORWARD)); 55 PetscCall(VecScatterEnd(ctx,x,y,INSERT_VALUES,SCATTER_FORWARD)); 56 57 PetscCall(PetscViewerASCIIPushSynchronized(PETSC_VIEWER_STDOUT_WORLD)); 58 PetscCall(PetscViewerASCIISynchronizedPrintf(PETSC_VIEWER_STDOUT_WORLD,"----\n")); 59 PetscCall(PetscViewerGetSubViewer(PETSC_VIEWER_STDOUT_WORLD,PETSC_COMM_SELF,&sviewer)); 60 PetscCall(VecView(y,sviewer)); fflush(stdout); 61 PetscCall(PetscViewerRestoreSubViewer(PETSC_VIEWER_STDOUT_WORLD,PETSC_COMM_SELF,&sviewer)); 62 PetscCall(PetscViewerFlush(PETSC_VIEWER_STDOUT_WORLD)); 63 PetscCall(PetscViewerASCIIPopSynchronized(PETSC_VIEWER_STDOUT_WORLD)); 64 65 PetscCall(VecScatterDestroy(&ctx)); 66 67 PetscCall(VecDestroy(&x)); 68 PetscCall(VecDestroy(&y)); 69 PetscCall(ISDestroy(&is1)); 70 PetscCall(ISDestroy(&is2)); 71 72 PetscCall(PetscFinalize()); 73 return 0; 74 } 75 76 /*TEST 77 78 testset: 79 nsize: 3 80 output_file: output/ex24_1.out 81 filter: grep -v " type:" 82 test: 83 suffix: standard 84 args: -vec_type standard 85 test: 86 requires: cuda 87 suffix: cuda 88 args: -vec_type cuda 89 test: 90 requires: viennacl 91 suffix: viennacl 92 args: -vec_type viennacl 93 94 TEST*/ 95