1*97929ea7SJunchao Zhang 2*97929ea7SJunchao Zhang static char help[]= "Scatters from a parallel vector to a sequential vector. \n\ 3*97929ea7SJunchao Zhang uses block index sets\n\n"; 4*97929ea7SJunchao Zhang 5*97929ea7SJunchao Zhang #include <petscvec.h> 6*97929ea7SJunchao Zhang 7*97929ea7SJunchao Zhang int main(int argc,char **argv) 8*97929ea7SJunchao Zhang { 9*97929ea7SJunchao Zhang PetscErrorCode ierr; 10*97929ea7SJunchao Zhang PetscInt bs=1,n=5,i,low; 11*97929ea7SJunchao Zhang PetscInt ix0[3] = {5,7,9},iy0[3] = {1,2,4},ix1[3] = {2,3,4},iy1[3] = {0,1,3}; 12*97929ea7SJunchao Zhang PetscMPIInt size,rank; 13*97929ea7SJunchao Zhang PetscScalar *array; 14*97929ea7SJunchao Zhang Vec x,y; 15*97929ea7SJunchao Zhang IS isx,isy; 16*97929ea7SJunchao Zhang VecScatter ctx; 17*97929ea7SJunchao Zhang 18*97929ea7SJunchao Zhang ierr = PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr; 19*97929ea7SJunchao Zhang ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRQ(ierr); 20*97929ea7SJunchao Zhang ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr); 21*97929ea7SJunchao Zhang 22*97929ea7SJunchao Zhang if (size <2) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_WRONG_MPI_SIZE,"Must run more than one processor"); 23*97929ea7SJunchao Zhang 24*97929ea7SJunchao Zhang ierr = PetscOptionsGetInt(NULL,NULL,"-bs",&bs,NULL);CHKERRQ(ierr); 25*97929ea7SJunchao Zhang n = bs*n; 26*97929ea7SJunchao Zhang 27*97929ea7SJunchao Zhang /* Create vector x over shared memory */ 28*97929ea7SJunchao Zhang ierr = VecCreate(PETSC_COMM_WORLD,&x);CHKERRQ(ierr); 29*97929ea7SJunchao Zhang ierr = VecSetSizes(x,n,PETSC_DECIDE);CHKERRQ(ierr); 30*97929ea7SJunchao Zhang ierr = VecSetFromOptions(x);CHKERRQ(ierr); 31*97929ea7SJunchao Zhang 32*97929ea7SJunchao Zhang ierr = VecGetOwnershipRange(x,&low,NULL);CHKERRQ(ierr); 33*97929ea7SJunchao Zhang ierr = VecGetArray(x,&array);CHKERRQ(ierr); 34*97929ea7SJunchao Zhang for (i=0; i<n; i++) { 35*97929ea7SJunchao Zhang array[i] = (PetscScalar)(i + low); 36*97929ea7SJunchao Zhang } 37*97929ea7SJunchao Zhang ierr = VecRestoreArray(x,&array);CHKERRQ(ierr); 38*97929ea7SJunchao Zhang 39*97929ea7SJunchao Zhang /* Create a sequential vector y */ 40*97929ea7SJunchao Zhang ierr = VecCreateSeq(PETSC_COMM_SELF,n,&y);CHKERRQ(ierr); 41*97929ea7SJunchao Zhang ierr = VecSet(y,0.0);CHKERRQ(ierr); 42*97929ea7SJunchao Zhang 43*97929ea7SJunchao Zhang /* Create two index sets */ 44*97929ea7SJunchao Zhang if (!rank) { 45*97929ea7SJunchao Zhang ierr = ISCreateBlock(PETSC_COMM_SELF,bs,3,ix0,PETSC_COPY_VALUES,&isx);CHKERRQ(ierr); 46*97929ea7SJunchao Zhang ierr = ISCreateBlock(PETSC_COMM_SELF,bs,3,iy0,PETSC_COPY_VALUES,&isy);CHKERRQ(ierr); 47*97929ea7SJunchao Zhang } else { 48*97929ea7SJunchao Zhang ierr = ISCreateBlock(PETSC_COMM_SELF,bs,3,ix1,PETSC_COPY_VALUES,&isx);CHKERRQ(ierr); 49*97929ea7SJunchao Zhang ierr = ISCreateBlock(PETSC_COMM_SELF,bs,3,iy1,PETSC_COPY_VALUES,&isy);CHKERRQ(ierr); 50*97929ea7SJunchao Zhang } 51*97929ea7SJunchao Zhang 52*97929ea7SJunchao Zhang if (rank == 10) { 53*97929ea7SJunchao Zhang ierr = PetscPrintf(PETSC_COMM_SELF,"\n[%d] isx:\n",rank);CHKERRQ(ierr); 54*97929ea7SJunchao Zhang ierr = ISView(isx,PETSC_VIEWER_STDOUT_SELF);CHKERRQ(ierr); 55*97929ea7SJunchao Zhang } 56*97929ea7SJunchao Zhang 57*97929ea7SJunchao Zhang ierr = VecScatterCreate(x,isx,y,isy,&ctx);CHKERRQ(ierr); 58*97929ea7SJunchao Zhang ierr = VecScatterSetFromOptions(ctx);CHKERRQ(ierr); 59*97929ea7SJunchao Zhang 60*97929ea7SJunchao Zhang /* Test forward vecscatter */ 61*97929ea7SJunchao Zhang ierr = VecScatterBegin(ctx,x,y,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 62*97929ea7SJunchao Zhang ierr = VecScatterEnd(ctx,x,y,ADD_VALUES,SCATTER_FORWARD);CHKERRQ(ierr); 63*97929ea7SJunchao Zhang if (rank == 0) { 64*97929ea7SJunchao Zhang ierr = PetscPrintf(PETSC_COMM_SELF,"[%d] y:\n",rank);CHKERRQ(ierr); 65*97929ea7SJunchao Zhang ierr = VecView(y,PETSC_VIEWER_STDOUT_SELF);CHKERRQ(ierr); 66*97929ea7SJunchao Zhang } 67*97929ea7SJunchao Zhang 68*97929ea7SJunchao Zhang /* Test reverse vecscatter */ 69*97929ea7SJunchao Zhang ierr = VecScale(y,-1.0);CHKERRQ(ierr); 70*97929ea7SJunchao Zhang if (rank) { 71*97929ea7SJunchao Zhang ierr = VecScale(y,1.0/(size - 1));CHKERRQ(ierr); 72*97929ea7SJunchao Zhang } 73*97929ea7SJunchao Zhang 74*97929ea7SJunchao Zhang ierr = VecScatterBegin(ctx,y,x,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 75*97929ea7SJunchao Zhang ierr = VecScatterEnd(ctx,y,x,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr); 76*97929ea7SJunchao Zhang ierr = VecView(x,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); 77*97929ea7SJunchao Zhang 78*97929ea7SJunchao Zhang /* Free spaces */ 79*97929ea7SJunchao Zhang ierr = VecScatterDestroy(&ctx);CHKERRQ(ierr); 80*97929ea7SJunchao Zhang ierr = ISDestroy(&isx);CHKERRQ(ierr); 81*97929ea7SJunchao Zhang ierr = ISDestroy(&isy);CHKERRQ(ierr); 82*97929ea7SJunchao Zhang ierr = VecDestroy(&x);CHKERRQ(ierr); 83*97929ea7SJunchao Zhang ierr = VecDestroy(&y);CHKERRQ(ierr); 84*97929ea7SJunchao Zhang ierr = PetscFinalize(); 85*97929ea7SJunchao Zhang return ierr; 86*97929ea7SJunchao Zhang } 87*97929ea7SJunchao Zhang 88*97929ea7SJunchao Zhang /*TEST 89*97929ea7SJunchao Zhang 90*97929ea7SJunchao Zhang test: 91*97929ea7SJunchao Zhang nsize: 3 92*97929ea7SJunchao Zhang 93*97929ea7SJunchao Zhang TEST*/ 94