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 PetscErrorCode ierr; 15 PetscMPIInt size; 16 PetscInt ma,na,mb,nb; 17 18 ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr; 19 ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRMPI(ierr); 20 if (size != 1) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,"This is a uniprocessor example only!"); 21 22 /* read the two matrices, A and B */ 23 ierr = PetscOptionsGetString(NULL,NULL,"-fA",file[0],sizeof(file[0]),&flg);CHKERRQ(ierr); 24 if (!flg) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_USER,"Must indicate binary file with the -fA options"); 25 ierr = PetscOptionsGetString(NULL,NULL,"-fB",file[1],sizeof(file[1]),&flg);CHKERRQ(ierr); 26 if (!flg) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_USER,"Must indicate binary file with the -fP options"); 27 28 /* Load matrices */ 29 ierr = PetscViewerBinaryOpen(PETSC_COMM_WORLD,file[0],FILE_MODE_READ,&fd);CHKERRQ(ierr); 30 ierr = MatCreate(PETSC_COMM_WORLD,&A);CHKERRQ(ierr); 31 ierr = MatLoad(A,fd);CHKERRQ(ierr); 32 ierr = PetscViewerDestroy(&fd);CHKERRQ(ierr); 33 printf("\n A:\n"); 34 printf("----------------------\n"); 35 ierr = MatView(A,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); 36 ierr = MatGetSize(A,&ma,&na);CHKERRQ(ierr); 37 38 ierr = PetscViewerBinaryOpen(PETSC_COMM_WORLD,file[1],FILE_MODE_READ,&fd);CHKERRQ(ierr); 39 ierr = MatCreate(PETSC_COMM_WORLD,&B);CHKERRQ(ierr); 40 ierr = MatLoad(B,fd);CHKERRQ(ierr); 41 ierr = PetscViewerDestroy(&fd);CHKERRQ(ierr); 42 printf("\n B:\n"); 43 printf("----------------------\n"); 44 ierr = MatView(B,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); 45 ierr = MatGetSize(B,&mb,&nb);CHKERRQ(ierr); 46 47 /* Compute B = -A + B */ 48 if (ma != mb || na != nb) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_SIZ,"nonconforming matrix size"); 49 ierr = MatAXPY(B,-1.0,A,DIFFERENT_NONZERO_PATTERN);CHKERRQ(ierr); 50 printf("\n B - A:\n"); 51 printf("----------------------\n"); 52 ierr = MatView(B,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr); 53 54 ierr = MatDestroy(&B);CHKERRQ(ierr); 55 ierr = MatDestroy(&A);CHKERRQ(ierr); 56 ierr = PetscFinalize(); 57 return ierr; 58 } 59