Actual source code: mmloader.c

  1: #include "mmloader.h"

  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;

 13:   /* Read in matrix */
 14:   PetscFunctionBeginUser;
 15:   PetscCall(PetscFOpen(PETSC_COMM_SELF, filein, "r", &file));
 16:   PetscCheck(mm_read_banner(file, &matcode) == 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Could not process Matrix Market banner.");
 17:   /*  This is how one can screen matrix types if their application */
 18:   /*  only supports a subset of the Matrix Market data types.      */
 19:   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));

 21:   if (mm_is_symmetric(matcode)) symmetric = PETSC_TRUE;
 22:   if (mm_is_skew(matcode)) skew = PETSC_TRUE;

 24:   /* Find out size of sparse matrix .... */
 25:   PetscCheck(mm_read_mtx_crd_size(file, &M, &N, &nz) == 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Size of sparse matrix is wrong.");

 27:   /* Reserve memory for matrices */
 28:   PetscCall(PetscMalloc4(nz, &ia, nz, &ja, nz, &val, M, &rownz));
 29:   for (i = 0; i < M; i++) rownz[i] = 0;

 31:   /* NOTE: when reading in doubles, ANSI C requires the use of the "l"  */
 32:   /*   specifier as in "%lg", "%lf", "%le", otherwise errors will occur */
 33:   /*  (ANSI C X3.159-1989, Sec. 4.9.6.2, p. 136 lines 13-15)            */
 34:   for (i = 0; i < nz; i++) {
 35:     ninput = fscanf(file, "%d %d %lg\n", &ia[i], &ja[i], &val[i]);
 36:     PetscCheck(ninput >= 3, PETSC_COMM_SELF, PETSC_ERR_FILE_UNEXPECTED, "Badly formatted input file");
 37:     ia[i]--;
 38:     ja[i]--;                              /* adjust from 1-based to 0-based */
 39:     if ((symmetric && aijonly) || skew) { /* transpose */
 40:       rownz[ia[i]]++;
 41:       rownz[ja[i]]++;
 42:     } else rownz[ia[i]]++;
 43:   }
 44:   PetscCall(PetscFClose(PETSC_COMM_SELF, file));

 46:   /* Create, preallocate, and then assemble the matrix */
 47:   PetscCall(MatCreate(PETSC_COMM_SELF, A));
 48:   PetscCall(MatSetSizes(*A, PETSC_DECIDE, PETSC_DECIDE, M, N));

 50:   if (symmetric && !aijonly) {
 51:     PetscCall(MatSetType(*A, MATSEQSBAIJ));
 52:     PetscCall(MatSetFromOptions(*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(MatSeqAIJSetPreallocation(*A, 0, rownz));
 60:     PetscCall(PetscObjectTypeCompare((PetscObject)(*A), MATSEQAIJ, &sametype));
 61:     PetscCheck(sametype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Only AIJ and SBAIJ are supported. Your mattype is not supported");
 62:   }
 63:   /* Add values to the matrix, these correspond to lower triangular part for symmetric or skew matrices */
 64:   for (j = 0; j < nz; j++) PetscCall(MatSetValues(*A, 1, &ia[j], 1, &ja[j], &val[j], INSERT_VALUES));

 66:   /* Add values to upper triangular part for some cases */
 67:   if (symmetric && aijonly) {
 68:     /* MatrixMarket matrix stores symm matrix in lower triangular part. Take its transpose */
 69:     for (j = 0; j < nz; j++) PetscCall(MatSetValues(*A, 1, &ja[j], 1, &ia[j], &val[j], INSERT_VALUES));
 70:   }
 71:   if (skew) {
 72:     for (j = 0; j < nz; j++) {
 73:       val[j] = -val[j];
 74:       PetscCall(MatSetValues(*A, 1, &ja[j], 1, &ia[j], &val[j], INSERT_VALUES));
 75:     }
 76:   }
 77:   PetscCall(MatAssemblyBegin(*A, MAT_FINAL_ASSEMBLY));
 78:   PetscCall(MatAssemblyEnd(*A, MAT_FINAL_ASSEMBLY));
 79:   PetscCall(PetscFree4(ia, ja, val, rownz));
 80:   PetscFunctionReturn(PETSC_SUCCESS);
 81: }