Actual source code: ex124.c
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";
6: #include <petscmat.h>
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;
17: PetscInitialize(&argc,&args,(char*)0,help);
18: MPI_Comm_size(PETSC_COMM_WORLD,&size);
21: /* read the two matrices, A and B */
22: PetscOptionsGetString(NULL,NULL,"-fA",file[0],sizeof(file[0]),&flg);
24: PetscOptionsGetString(NULL,NULL,"-fB",file[1],sizeof(file[1]),&flg);
27: /* Load matrices */
28: PetscViewerBinaryOpen(PETSC_COMM_WORLD,file[0],FILE_MODE_READ,&fd);
29: MatCreate(PETSC_COMM_WORLD,&A);
30: MatLoad(A,fd);
31: PetscViewerDestroy(&fd);
32: printf("\n A:\n");
33: printf("----------------------\n");
34: MatView(A,PETSC_VIEWER_STDOUT_WORLD);
35: MatGetSize(A,&ma,&na);
37: PetscViewerBinaryOpen(PETSC_COMM_WORLD,file[1],FILE_MODE_READ,&fd);
38: MatCreate(PETSC_COMM_WORLD,&B);
39: MatLoad(B,fd);
40: PetscViewerDestroy(&fd);
41: printf("\n B:\n");
42: printf("----------------------\n");
43: MatView(B,PETSC_VIEWER_STDOUT_WORLD);
44: MatGetSize(B,&mb,&nb);
46: /* Compute B = -A + B */
48: MatAXPY(B,-1.0,A,DIFFERENT_NONZERO_PATTERN);
49: printf("\n B - A:\n");
50: printf("----------------------\n");
51: MatView(B,PETSC_VIEWER_STDOUT_WORLD);
53: MatDestroy(&B);
54: MatDestroy(&A);
55: PetscFinalize();
56: return 0;
57: }