Actual source code: ex1.c
2: static char help[] = "Reads a PETSc matrix and vector from a file and reorders it.\n\
3: -f0 <input_file> : first file to load (small system)\n\
4: -f1 <input_file> : second file to load (larger system)\n\n";
6: /*
7: Include "petscmat.h" so that we can use matrices.
8: automatically includes:
9: petscsys.h - base PETSc routines petscvec.h - vectors
10: petscmat.h - matrices
11: petscis.h - index sets petscviewer.h - viewers
12: */
13: #include <petscmat.h>
15: int main(int argc,char **args)
16: {
17: Mat A; /* matrix */
18: PetscViewer fd; /* viewer */
19: char file[PETSC_MAX_PATH_LEN]; /* input file name */
20: IS isrow,iscol; /* row and column permutations */
21: MatOrderingType rtype = MATORDERINGRCM;
22: PetscBool flg;
24: PetscInitialize(&argc,&args,(char*)0,help);
25: /*
26: Determine files from which we read the two linear systems
27: (matrix and right-hand-side vector).
28: */
29: PetscOptionsGetString(NULL,NULL,"-f",file,sizeof(file),&flg);
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: */
45: /* - - - - - - - - - - - New Stage - - - - - - - - - - - - -
46: Load system i
47: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
49: /*
50: Open binary file. Note that we use FILE_MODE_READ to indicate
51: reading from this file.
52: */
53: PetscViewerBinaryOpen(PETSC_COMM_WORLD,file,FILE_MODE_READ,&fd);
55: /*
56: Load the matrix; then destroy the viewer.
57: */
58: MatCreate(PETSC_COMM_WORLD,&A);
59: MatSetType(A,MATSEQAIJ);
60: MatLoad(A,fd);
61: PetscViewerDestroy(&fd);
63: MatGetOrdering(A,rtype,&isrow,&iscol);
64: ISView(isrow,PETSC_VIEWER_STDOUT_WORLD);
66: /*
67: Free work space. All PETSc objects should be destroyed when they
68: are no longer needed.
69: */
70: MatDestroy(&A);
71: ISDestroy(&isrow);
72: ISDestroy(&iscol);
74: PetscFinalize();
75: return 0;
76: }
78: /*TEST
80: test:
81: requires: datafilespath double !complex !defined(PETSC_USE_64BIT_INDICES)
82: args: -f ${DATAFILESPATH}/matrices/medium -viewer_binary_skip_info
84: TEST*/