MatFactorInfo

Data passed into the matrix factorization routines

Synopsis

typedef struct {
  PetscReal     shiftnz;        /* scaling of identity added to matrix to prevent zero pivots */
  PetscReal     shiftpd;        /* if true, shift until positive pivots */
  PetscReal     shift_fraction; /* record shift fraction taken */
  PetscReal     diagonal_fill;  /* force diagonal to fill in if initially not filled */
  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 */
} MatFactorInfo;

In Fortran these are simply double precision arrays of size MAT_FACTORINFO_SIZE

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

MatFactorInfo

Synopsis

See Also