1 2 static char help[] = "Tests binary I/O of matrices and illustrates user-defined event logging.\n\n"; 3 4 #include <petscmat.h> 5 6 /* Note: Most applications would not read and write the same matrix within 7 the same program. This example is intended only to demonstrate 8 both input and output. */ 9 10 int main(int argc,char **args) 11 { 12 Mat C; 13 PetscScalar v; 14 PetscInt i,j,Ii,J,Istart,Iend,N,m = 4,n = 4; 15 PetscMPIInt rank,size; 16 PetscErrorCode ierr; 17 PetscViewer viewer; 18 #if defined(PETSC_USE_LOG) 19 PetscLogEvent MATRIX_GENERATE,MATRIX_READ; 20 #endif 21 22 ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr; 23 CHKERRMPI(MPI_Comm_rank(PETSC_COMM_WORLD,&rank)); 24 CHKERRMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size)); 25 CHKERRQ(PetscOptionsGetInt(NULL,NULL,"-m",&m,NULL)); 26 CHKERRQ(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL)); 27 N = m*n; 28 29 /* PART 1: Generate matrix, then write it in binary format */ 30 31 CHKERRQ(PetscLogEventRegister("Generate Matrix",0,&MATRIX_GENERATE)); 32 CHKERRQ(PetscLogEventBegin(MATRIX_GENERATE,0,0,0,0)); 33 34 /* Generate matrix */ 35 CHKERRQ(MatCreate(PETSC_COMM_WORLD,&C)); 36 CHKERRQ(MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,N,N)); 37 CHKERRQ(MatSetFromOptions(C)); 38 CHKERRQ(MatSetUp(C)); 39 CHKERRQ(MatGetOwnershipRange(C,&Istart,&Iend)); 40 for (Ii=Istart; Ii<Iend; Ii++) { 41 v = -1.0; i = Ii/n; j = Ii - i*n; 42 if (i>0) {J = Ii - n; CHKERRQ(MatSetValues(C,1,&Ii,1,&J,&v,ADD_VALUES));} 43 if (i<m-1) {J = Ii + n; CHKERRQ(MatSetValues(C,1,&Ii,1,&J,&v,ADD_VALUES));} 44 if (j>0) {J = Ii - 1; CHKERRQ(MatSetValues(C,1,&Ii,1,&J,&v,ADD_VALUES));} 45 if (j<n-1) {J = Ii + 1; CHKERRQ(MatSetValues(C,1,&Ii,1,&J,&v,ADD_VALUES));} 46 v = 4.0; CHKERRQ(MatSetValues(C,1,&Ii,1,&Ii,&v,ADD_VALUES)); 47 } 48 CHKERRQ(MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY)); 49 CHKERRQ(MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY)); 50 CHKERRQ(MatView(C,PETSC_VIEWER_STDOUT_WORLD)); 51 52 CHKERRQ(PetscPrintf(PETSC_COMM_WORLD,"writing matrix in binary to matrix.dat ...\n")); 53 CHKERRQ(PetscViewerBinaryOpen(PETSC_COMM_WORLD,"matrix.dat",FILE_MODE_WRITE,&viewer)); 54 CHKERRQ(MatView(C,viewer)); 55 CHKERRQ(PetscViewerDestroy(&viewer)); 56 CHKERRQ(MatDestroy(&C)); 57 CHKERRQ(PetscLogEventEnd(MATRIX_GENERATE,0,0,0,0)); 58 59 /* PART 2: Read in matrix in binary format */ 60 61 /* All processors wait until test matrix has been dumped */ 62 CHKERRMPI(MPI_Barrier(PETSC_COMM_WORLD)); 63 64 CHKERRQ(PetscLogEventRegister("Read Matrix",0,&MATRIX_READ)); 65 CHKERRQ(PetscLogEventBegin(MATRIX_READ,0,0,0,0)); 66 CHKERRQ(PetscPrintf(PETSC_COMM_WORLD,"reading matrix in binary from matrix.dat ...\n")); 67 CHKERRQ(PetscViewerBinaryOpen(PETSC_COMM_WORLD,"matrix.dat",FILE_MODE_READ,&viewer)); 68 CHKERRQ(MatCreate(PETSC_COMM_WORLD,&C)); 69 CHKERRQ(MatLoad(C,viewer)); 70 CHKERRQ(PetscViewerDestroy(&viewer)); 71 CHKERRQ(PetscLogEventEnd(MATRIX_READ,0,0,0,0)); 72 CHKERRQ(MatView(C,PETSC_VIEWER_STDOUT_WORLD)); 73 74 /* Free data structures */ 75 CHKERRQ(MatDestroy(&C)); 76 77 ierr = PetscFinalize(); 78 return ierr; 79 } 80 81 /*TEST 82 83 test: 84 filter: grep -v "MPI processes" 85 86 TEST*/ 87