1 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"; 5 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> 14 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; 23 24 PetscFunctionBeginUser; 25 PetscCall(PetscInitialize(&argc, &args, (char *)0, help)); 26 /* 27 Determine files from which we read the two linear systems 28 (matrix and right-hand-side vector). 29 */ 30 PetscCall(PetscOptionsGetString(NULL, NULL, "-f", file, sizeof(file), &flg)); 31 PetscCheck(flg, PETSC_COMM_WORLD, PETSC_ERR_USER, "Must indicate binary file with the -f option"); 32 33 /* ----------------------------------------------------------- 34 Beginning of loop 35 ----------------------------------------------------------- */ 36 /* 37 Loop through the reordering 2 times. 38 - The intention here is to preload and solve a small system; 39 then load another (larger) system and solve it as well. 40 This process preloads the instructions with the smaller 41 system so that more accurate performance monitoring (via 42 -log_view) can be done with the larger one (that actually 43 is the system of interest). 44 */ 45 46 /* - - - - - - - - - - - New Stage - - - - - - - - - - - - - 47 Load system i 48 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ 49 50 /* 51 Open binary file. Note that we use FILE_MODE_READ to indicate 52 reading from this file. 53 */ 54 PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, file, FILE_MODE_READ, &fd)); 55 56 /* 57 Load the matrix; then destroy the viewer. 58 */ 59 PetscCall(MatCreate(PETSC_COMM_WORLD, &A)); 60 PetscCall(MatSetType(A, MATSEQAIJ)); 61 PetscCall(MatLoad(A, fd)); 62 PetscCall(PetscViewerDestroy(&fd)); 63 64 PetscCall(MatGetOrdering(A, rtype, &isrow, &iscol)); 65 PetscCall(ISView(isrow, PETSC_VIEWER_STDOUT_WORLD)); 66 67 /* 68 Free work space. All PETSc objects should be destroyed when they 69 are no longer needed. 70 */ 71 PetscCall(MatDestroy(&A)); 72 PetscCall(ISDestroy(&isrow)); 73 PetscCall(ISDestroy(&iscol)); 74 75 PetscCall(PetscFinalize()); 76 return 0; 77 } 78 79 /*TEST 80 81 test: 82 requires: datafilespath double !complex !defined(PETSC_USE_64BIT_INDICES) 83 args: -f ${DATAFILESPATH}/matrices/medium -viewer_binary_skip_info 84 85 TEST*/ 86