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 PetscViewer viewer; 17 #if defined(PETSC_USE_LOG) 18 PetscLogEvent MATRIX_GENERATE,MATRIX_READ; 19 #endif 20 21 PetscCall(PetscInitialize(&argc,&args,(char*)0,help)); 22 PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD,&rank)); 23 PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size)); 24 PetscCall(PetscOptionsGetInt(NULL,NULL,"-m",&m,NULL)); 25 PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL)); 26 N = m*n; 27 28 /* PART 1: Generate matrix, then write it in binary format */ 29 30 PetscCall(PetscLogEventRegister("Generate Matrix",0,&MATRIX_GENERATE)); 31 PetscCall(PetscLogEventBegin(MATRIX_GENERATE,0,0,0,0)); 32 33 /* Generate matrix */ 34 PetscCall(MatCreate(PETSC_COMM_WORLD,&C)); 35 PetscCall(MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,N,N)); 36 PetscCall(MatSetFromOptions(C)); 37 PetscCall(MatSetUp(C)); 38 PetscCall(MatGetOwnershipRange(C,&Istart,&Iend)); 39 for (Ii=Istart; Ii<Iend; Ii++) { 40 v = -1.0; i = Ii/n; j = Ii - i*n; 41 if (i>0) {J = Ii - n; PetscCall(MatSetValues(C,1,&Ii,1,&J,&v,ADD_VALUES));} 42 if (i<m-1) {J = Ii + n; PetscCall(MatSetValues(C,1,&Ii,1,&J,&v,ADD_VALUES));} 43 if (j>0) {J = Ii - 1; PetscCall(MatSetValues(C,1,&Ii,1,&J,&v,ADD_VALUES));} 44 if (j<n-1) {J = Ii + 1; PetscCall(MatSetValues(C,1,&Ii,1,&J,&v,ADD_VALUES));} 45 v = 4.0; PetscCall(MatSetValues(C,1,&Ii,1,&Ii,&v,ADD_VALUES)); 46 } 47 PetscCall(MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY)); 48 PetscCall(MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY)); 49 PetscCall(MatView(C,PETSC_VIEWER_STDOUT_WORLD)); 50 51 PetscCall(PetscPrintf(PETSC_COMM_WORLD,"writing matrix in binary to matrix.dat ...\n")); 52 PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD,"matrix.dat",FILE_MODE_WRITE,&viewer)); 53 PetscCall(MatView(C,viewer)); 54 PetscCall(PetscViewerDestroy(&viewer)); 55 PetscCall(MatDestroy(&C)); 56 PetscCall(PetscLogEventEnd(MATRIX_GENERATE,0,0,0,0)); 57 58 /* PART 2: Read in matrix in binary format */ 59 60 /* All processors wait until test matrix has been dumped */ 61 PetscCallMPI(MPI_Barrier(PETSC_COMM_WORLD)); 62 63 PetscCall(PetscLogEventRegister("Read Matrix",0,&MATRIX_READ)); 64 PetscCall(PetscLogEventBegin(MATRIX_READ,0,0,0,0)); 65 PetscCall(PetscPrintf(PETSC_COMM_WORLD,"reading matrix in binary from matrix.dat ...\n")); 66 PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD,"matrix.dat",FILE_MODE_READ,&viewer)); 67 PetscCall(MatCreate(PETSC_COMM_WORLD,&C)); 68 PetscCall(MatLoad(C,viewer)); 69 PetscCall(PetscViewerDestroy(&viewer)); 70 PetscCall(PetscLogEventEnd(MATRIX_READ,0,0,0,0)); 71 PetscCall(MatView(C,PETSC_VIEWER_STDOUT_WORLD)); 72 73 /* Free data structures */ 74 PetscCall(MatDestroy(&C)); 75 76 PetscCall(PetscFinalize()); 77 return 0; 78 } 79 80 /*TEST 81 82 test: 83 filter: grep -v " MPI process" 84 85 TEST*/ 86