1 static char help[] = "Reads a PETSc matrix and vector from a file and reorders it.\n\
2 -f0 <input_file> : first file to load (small system)\n\
3 -f1 <input_file> : second file to load (larger system)\n\n";
4
5 /*
6 Include "petscmat.h" so that we can use matrices.
7 automatically includes:
8 petscsys.h - base PETSc routines petscvec.h - vectors
9 petscmat.h - matrices
10 petscis.h - index sets petscviewer.h - viewers
11 */
12 #include <petscmat.h>
13
main(int argc,char ** args)14 int main(int argc, char **args)
15 {
16 Mat A; /* matrix */
17 PetscViewer fd; /* viewer */
18 char file[PETSC_MAX_PATH_LEN]; /* input file name */
19 IS isrow, iscol; /* row and column permutations */
20 MatOrderingType rtype = MATORDERINGRCM;
21 PetscBool flg;
22
23 PetscFunctionBeginUser;
24 PetscCall(PetscInitialize(&argc, &args, NULL, help));
25 /*
26 Determine files from which we read the two linear systems
27 (matrix and right-hand-side vector).
28 */
29 PetscCall(PetscOptionsGetString(NULL, NULL, "-f", file, sizeof(file), &flg));
30 PetscCheck(flg, PETSC_COMM_WORLD, PETSC_ERR_USER, "Must indicate binary file with the -f option");
31
32 /* -----------------------------------------------------------
33 Beginning of loop
34 ----------------------------------------------------------- */
35 /*
36 Loop through the reordering 2 times.
37 - The intention here is to preload and solve a small system;
38 then load another (larger) system and solve it as well.
39 This process preloads the instructions with the smaller
40 system so that more accurate performance monitoring (via
41 -log_view) can be done with the larger one (that actually
42 is the system of interest).
43 */
44
45 /* - - - - - - - - - - - New Stage - - - - - - - - - - - - -
46 Load system i
47 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
48
49 /*
50 Open binary file. Note that we use FILE_MODE_READ to indicate
51 reading from this file.
52 */
53 PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, file, FILE_MODE_READ, &fd));
54
55 /*
56 Load the matrix; then destroy the viewer.
57 */
58 PetscCall(MatCreate(PETSC_COMM_WORLD, &A));
59 PetscCall(MatSetType(A, MATSEQAIJ));
60 PetscCall(MatLoad(A, fd));
61 PetscCall(PetscViewerDestroy(&fd));
62
63 PetscCall(MatGetOrdering(A, rtype, &isrow, &iscol));
64 PetscCall(ISView(isrow, PETSC_VIEWER_STDOUT_WORLD));
65
66 /*
67 Free work space. All PETSc objects should be destroyed when they
68 are no longer needed.
69 */
70 PetscCall(MatDestroy(&A));
71 PetscCall(ISDestroy(&isrow));
72 PetscCall(ISDestroy(&iscol));
73
74 PetscCall(PetscFinalize());
75 return 0;
76 }
77
78 /*TEST
79
80 test:
81 requires: datafilespath double !complex !defined(PETSC_USE_64BIT_INDICES)
82 args: -f ${DATAFILESPATH}/matrices/medium -viewer_binary_skip_info
83
84 TEST*/
85