1 2 static char help[] = "Scatters from a parallel vector to a sequential vector.\n\ 3 Using a blocked send and a strided receive.\n\n"; 4 5 /* 6 0 1 2 3 | 4 5 6 7 || 8 9 10 11 7 8 Scatter first and third block to first processor and 9 second and third block to second processor 10 */ 11 12 #include <petscvec.h> 13 14 int main(int argc,char **argv) 15 { 16 PetscErrorCode ierr; 17 PetscInt i,blocks[2],nlocal; 18 PetscMPIInt size,rank; 19 PetscScalar value; 20 Vec x,y; 21 IS is1,is2; 22 VecScatter ctx = 0; 23 PetscViewer subviewer; 24 25 ierr = PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr; 26 ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRMPI(ierr); 27 ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRMPI(ierr); 28 29 if (size != 2) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_WRONG_MPI_SIZE,"Must run with 2 processors"); 30 31 /* create two vectors */ 32 if (!rank) nlocal = 8; 33 else nlocal = 4; 34 ierr = VecCreate(PETSC_COMM_WORLD,&x);CHKERRQ(ierr); 35 ierr = VecSetSizes(x,nlocal,12);CHKERRQ(ierr); 36 ierr = VecSetFromOptions(x);CHKERRQ(ierr); 37 ierr = VecCreate(PETSC_COMM_SELF,&y);CHKERRQ(ierr); 38 ierr = VecSetSizes(y,8,PETSC_DECIDE);CHKERRQ(ierr); 39 ierr = VecSetFromOptions(y);CHKERRQ(ierr); 40 41 /* create two index sets */ 42 if (!rank) { 43 blocks[0] = 0; blocks[1] = 2; 44 } else { 45 blocks[0] = 1; blocks[1] = 2; 46 } 47 ierr = ISCreateBlock(PETSC_COMM_SELF,4,2,blocks,PETSC_COPY_VALUES,&is1);CHKERRQ(ierr); 48 ierr = ISCreateStride(PETSC_COMM_SELF,8,0,1,&is2);CHKERRQ(ierr); 49 50 for (i=0; i<12; i++) { 51 value = i; 52 ierr = VecSetValues(x,1,&i,&value,INSERT_VALUES);CHKERRQ(ierr); 53 } 54 ierr = VecAssemblyBegin(x);CHKERRQ(ierr); 55 ierr = VecAssemblyEnd(x);CHKERRQ(ierr); 56 57 ierr = VecScatterCreate(x,is1,y,is2,&ctx);CHKERRQ(ierr); 58 ierr = VecScatterBegin(ctx,x,y,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 59 ierr = VecScatterEnd(ctx,x,y,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 60 ierr = VecScatterDestroy(&ctx);CHKERRQ(ierr); 61 62 ierr = PetscViewerGetSubViewer(PETSC_VIEWER_STDOUT_WORLD,PETSC_COMM_SELF,&subviewer);CHKERRQ(ierr); 63 ierr = VecView(y,subviewer);CHKERRQ(ierr); 64 ierr = PetscViewerRestoreSubViewer(PETSC_VIEWER_STDOUT_WORLD,PETSC_COMM_SELF,&subviewer);CHKERRQ(ierr); 65 66 ierr = VecDestroy(&x);CHKERRQ(ierr); 67 ierr = VecDestroy(&y);CHKERRQ(ierr); 68 ierr = ISDestroy(&is1);CHKERRQ(ierr); 69 ierr = ISDestroy(&is2);CHKERRQ(ierr); 70 71 ierr = PetscFinalize(); 72 return ierr; 73 } 74 75 76 77 /*TEST 78 79 testset: 80 nsize: 2 81 output_file: output/ex23_1.out 82 filter: grep -v " type:" 83 test: 84 suffix: standard 85 args: -vec_type standard 86 test: 87 requires: cuda 88 suffix: cuda 89 args: -vec_type cuda 90 test: 91 requires: viennacl 92 suffix: viennacl 93 args: -vec_type viennacl 94 test: 95 requires: kokkos_kernels 96 suffix: kokkos 97 args: -vec_type kokkos 98 TEST*/ 99