1 2 static char help[] = "Tests converting a matrix to another format with MatConvert().\n\n"; 3 4 #include <petscmat.h> 5 6 int main(int argc,char **args) 7 { 8 Mat C,A; 9 PetscInt i,j,m = 5,n = 4,Ii,J; 10 PetscMPIInt rank,size; 11 PetscScalar v; 12 char mtype[256]; 13 14 PetscFunctionBeginUser; 15 PetscCall(PetscInitialize(&argc,&args,(char*)0,help)); 16 PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD,&rank)); 17 18 /* This example does not work correctly for np > 2 */ 19 PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size)); 20 PetscCheck(size <= 2,PETSC_COMM_WORLD,PETSC_ERR_WRONG_MPI_SIZE,"Use np <= 2"); 21 22 /* Create the matrix for the five point stencil, YET AGAIN */ 23 PetscCall(MatCreate(PETSC_COMM_WORLD,&C)); 24 PetscCall(MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n)); 25 PetscCall(MatSetFromOptions(C)); 26 PetscCall(MatSetUp(C)); 27 for (i=0; i<m; i++) { 28 for (j=2*rank; j<2*rank+2; j++) { 29 v = -1.0; Ii = j + n*i; 30 if (i>0) {J = Ii - n; PetscCall(MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES));} 31 if (i<m-1) {J = Ii + n; PetscCall(MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES));} 32 if (j>0) {J = Ii - 1; PetscCall(MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES));} 33 if (j<n-1) {J = Ii + 1; PetscCall(MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES));} 34 v = 4.0; PetscCall(MatSetValues(C,1,&Ii,1,&Ii,&v,INSERT_VALUES)); 35 } 36 } 37 38 PetscCall(MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY)); 39 PetscCall(MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY)); 40 PetscCall(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO)); 41 PetscCall(MatView(C,PETSC_VIEWER_STDOUT_WORLD)); 42 PetscCall(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD)); 43 PetscCall(MatView(C,PETSC_VIEWER_STDOUT_WORLD)); 44 45 PetscCall(PetscStrcpy(mtype,MATSAME)); 46 PetscCall(PetscOptionsGetString(NULL,NULL,"-conv_mat_type",mtype,sizeof(mtype),NULL)); 47 PetscCall(MatConvert(C,mtype,MAT_INITIAL_MATRIX,&A)); 48 PetscCall(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_INFO)); 49 PetscCall(MatView(A,PETSC_VIEWER_STDOUT_WORLD)); 50 PetscCall(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD)); 51 PetscCall(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD,PETSC_VIEWER_ASCII_IMPL)); 52 PetscCall(MatView(A,PETSC_VIEWER_STDOUT_WORLD)); 53 PetscCall(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD)); 54 55 /* Free data structures */ 56 PetscCall(MatDestroy(&A)); 57 PetscCall(MatDestroy(&C)); 58 59 PetscCall(PetscFinalize()); 60 return 0; 61 } 62 63 /*TEST 64 65 test: 66 args: -conv_mat_type seqaij 67 68 TEST*/ 69