xref: /petsc/src/mat/tests/mmloader.c (revision 217f7fc6b7ccbb041bf230fae922d6b0eefae257)
1 #include "mmloader.h"
2 
3 PetscErrorCode MatCreateFromMTX(Mat *A, const char *filein, PetscBool aijonly)
4 {
5   MM_typecode  matcode;
6   FILE        *file;
7   PetscInt     M, N, ninput;
8   PetscInt    *ia, *ja;
9   PetscInt     i, j, nz, *rownz;
10   PetscScalar *val;
11   PetscBool    sametype, symmetric = PETSC_FALSE, skew = PETSC_FALSE;
12 
13   /* Read in matrix */
14   PetscCall(PetscFOpen(PETSC_COMM_SELF, filein, "r", &file));
15   PetscCheck(mm_read_banner(file, &matcode) == 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Could not process Matrix Market banner.");
16   /*  This is how one can screen matrix types if their application */
17   /*  only supports a subset of the Matrix Market data types.      */
18   PetscCheck(mm_is_matrix(matcode) && mm_is_sparse(matcode) && (mm_is_real(matcode) || mm_is_integer(matcode)), PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Input must be a sparse real or integer matrix. Market Market type: [%s]", mm_typecode_to_str(matcode));
19 
20   if (mm_is_symmetric(matcode)) symmetric = PETSC_TRUE;
21   if (mm_is_skew(matcode)) skew = PETSC_TRUE;
22 
23   /* Find out size of sparse matrix .... */
24   PetscCheck(mm_read_mtx_crd_size(file, &M, &N, &nz) == 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Size of sparse matrix is wrong.");
25 
26   /* Reserve memory for matrices */
27   PetscCall(PetscMalloc4(nz, &ia, nz, &ja, nz, &val, M, &rownz));
28   for (i = 0; i < M; i++) rownz[i] = 0;
29 
30   /* NOTE: when reading in doubles, ANSI C requires the use of the "l"  */
31   /*   specifier as in "%lg", "%lf", "%le", otherwise errors will occur */
32   /*  (ANSI C X3.159-1989, Sec. 4.9.6.2, p. 136 lines 13-15)            */
33   for (i = 0; i < nz; i++) {
34     ninput = fscanf(file, "%d %d %lg\n", &ia[i], &ja[i], &val[i]);
35     PetscCheck(ninput >= 3, PETSC_COMM_SELF, PETSC_ERR_FILE_UNEXPECTED, "Badly formatted input file");
36     ia[i]--;
37     ja[i]--;                              /* adjust from 1-based to 0-based */
38     if ((symmetric && aijonly) || skew) { /* transpose */
39       rownz[ia[i]]++;
40       rownz[ja[i]]++;
41     } else rownz[ia[i]]++;
42   }
43   PetscCall(PetscFClose(PETSC_COMM_SELF, file));
44 
45   /* Create, preallocate, and then assemble the matrix */
46   PetscCall(MatCreate(PETSC_COMM_SELF, A));
47   PetscCall(MatSetSizes(*A, PETSC_DECIDE, PETSC_DECIDE, M, N));
48 
49   if (symmetric && !aijonly) {
50     PetscCall(MatSetType(*A, MATSEQSBAIJ));
51     PetscCall(MatSetFromOptions(*A));
52     PetscCall(MatSetUp(*A));
53     PetscCall(MatSeqSBAIJSetPreallocation(*A, 1, 0, rownz));
54     PetscCall(PetscObjectTypeCompare((PetscObject)(*A), MATSEQSBAIJ, &sametype));
55     PetscCheck(sametype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Only AIJ and SBAIJ are supported. Your mattype is not supported");
56   } else {
57     PetscCall(MatSetType(*A, MATSEQAIJ));
58     PetscCall(MatSetFromOptions(*A));
59     PetscCall(MatSetUp(*A));
60     PetscCall(MatSeqAIJSetPreallocation(*A, 0, rownz));
61     PetscCall(PetscObjectTypeCompare((PetscObject)(*A), MATSEQAIJ, &sametype));
62     PetscCheck(sametype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Only AIJ and SBAIJ are supported. Your mattype is not supported");
63   }
64   /* Add values to the matrix, these correspond to lower triangular part for symmetric or skew matrices */
65   for (j = 0; j < nz; j++) PetscCall(MatSetValues(*A, 1, &ia[j], 1, &ja[j], &val[j], INSERT_VALUES));
66 
67   /* Add values to upper triangular part for some cases */
68   if (symmetric && aijonly) {
69     /* MatrixMarket matrix stores symm matrix in lower triangular part. Take its transpose */
70     for (j = 0; j < nz; j++) PetscCall(MatSetValues(*A, 1, &ja[j], 1, &ia[j], &val[j], INSERT_VALUES));
71   }
72   if (skew) {
73     for (j = 0; j < nz; j++) {
74       val[j] = -val[j];
75       PetscCall(MatSetValues(*A, 1, &ja[j], 1, &ia[j], &val[j], INSERT_VALUES));
76     }
77   }
78   PetscCall(MatAssemblyBegin(*A, MAT_FINAL_ASSEMBLY));
79   PetscCall(MatAssemblyEnd(*A, MAT_FINAL_ASSEMBLY));
80   PetscCall(PetscFree4(ia, ja, val, rownz));
81   return 0;
82 }
83