1 static char help[] = "Check the difference of the two matrices \n\ 2 Reads PETSc matrix A and B, then check B=A-B \n\ 3 Input parameters include\n\ 4 -fA <input_file> -fB <input_file> \n\n"; 5 6 #include <petscmat.h> 7 8 int main(int argc,char **args) 9 { 10 Mat A,B; 11 PetscViewer fd; 12 char file[2][PETSC_MAX_PATH_LEN]; 13 PetscBool flg; 14 PetscMPIInt size; 15 PetscInt ma,na,mb,nb; 16 17 PetscCall(PetscInitialize(&argc,&args,(char*)0,help)); 18 PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size)); 19 PetscCheck(size == 1,PETSC_COMM_WORLD,PETSC_ERR_WRONG_MPI_SIZE,"This is a uniprocessor example only!"); 20 21 /* read the two matrices, A and B */ 22 PetscCall(PetscOptionsGetString(NULL,NULL,"-fA",file[0],sizeof(file[0]),&flg)); 23 PetscCheck(flg,PETSC_COMM_WORLD,PETSC_ERR_USER,"Must indicate binary file with the -fA options"); 24 PetscCall(PetscOptionsGetString(NULL,NULL,"-fB",file[1],sizeof(file[1]),&flg)); 25 PetscCheck(flg,PETSC_COMM_WORLD,PETSC_ERR_USER,"Must indicate binary file with the -fP options"); 26 27 /* Load matrices */ 28 PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD,file[0],FILE_MODE_READ,&fd)); 29 PetscCall(MatCreate(PETSC_COMM_WORLD,&A)); 30 PetscCall(MatLoad(A,fd)); 31 PetscCall(PetscViewerDestroy(&fd)); 32 printf("\n A:\n"); 33 printf("----------------------\n"); 34 PetscCall(MatView(A,PETSC_VIEWER_STDOUT_WORLD)); 35 PetscCall(MatGetSize(A,&ma,&na)); 36 37 PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD,file[1],FILE_MODE_READ,&fd)); 38 PetscCall(MatCreate(PETSC_COMM_WORLD,&B)); 39 PetscCall(MatLoad(B,fd)); 40 PetscCall(PetscViewerDestroy(&fd)); 41 printf("\n B:\n"); 42 printf("----------------------\n"); 43 PetscCall(MatView(B,PETSC_VIEWER_STDOUT_WORLD)); 44 PetscCall(MatGetSize(B,&mb,&nb)); 45 46 /* Compute B = -A + B */ 47 PetscCheck(ma == mb && na == nb,PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"nonconforming matrix size"); 48 PetscCall(MatAXPY(B,-1.0,A,DIFFERENT_NONZERO_PATTERN)); 49 printf("\n B - A:\n"); 50 printf("----------------------\n"); 51 PetscCall(MatView(B,PETSC_VIEWER_STDOUT_WORLD)); 52 53 PetscCall(MatDestroy(&B)); 54 PetscCall(MatDestroy(&A)); 55 PetscCall(PetscFinalize()); 56 return 0; 57 } 58