petsc-3.7.5 2017-01-01

MatFactorInfo

Data passed into the matrix factorization routines, and information about the resulting factorization

Synopsis

typedef struct {
  PetscReal     diagonal_fill;  /* force diagonal to fill in if initially not filled */
  PetscReal     usedt;
  PetscReal     dt;             /* drop tolerance */
  PetscReal     dtcol;          /* tolerance for pivoting */
  PetscReal     dtcount;        /* maximum nonzeros to be allowed per row */
  PetscReal     fill;           /* expected fill, nonzeros in factored matrix/nonzeros in original matrix */
  PetscReal     levels;         /* ICC/ILU(levels) */
  PetscReal     pivotinblocks;  /* for BAIJ and SBAIJ matrices pivot in factorization on blocks, default 1.0
                                   factorization may be faster if do not pivot */
  PetscReal     zeropivot;      /* pivot is called zero if less than this */
  PetscReal     shifttype;      /* type of shift added to matrix factor to prevent zero pivots */
  PetscReal     shiftamount;     /* how large the shift is */
} MatFactorInfo;

In Fortran these are simply double precision arrays of size MAT_FACTORINFO_SIZE, that is use

    MatFactorInfo  info(MAT_FACTORINFO_SIZE)

Notes: These are not usually directly used by users, instead use PC type of LU, ILU, CHOLESKY or ICC.

You can use MatFactorInfoInitialize() to set default values.

MatFactorInfo

Synopsis

See Also