HP MLIB User's Guide Vol. 2 7th Ed.

Chapter 13 Sparse Linear Equations 901
Specify singularity treatment DSLEFF
INTEGER*8 iabort, ier
REAL*8 fudge, tol
REAL*8 global(150)
CALL DSLEFF(iabort, fudge, tol, global, ier)
INTEGER*8 iabort, ier
REAL*16 fudge, tol
REAL*8 global(150)
CALL QSLEFF(iabort, fudge, tol, global, ier)
INTEGER*8 iabort, ier
COMPLEX*8 fudge, tol
REAL*8 global(150)
CALL CSLEFF(iabort, fudge, tol, global, ier)
INTEGER*8 iabort, ier
COMPLEX*16 fudge, tol
REAL*8 global(150)
CALL ZSLEFF(iabort, fudge, tol, global, ier)
Input iabort Flag to specify when to terminate the factorization, as
follows:
iabort = 1 Terminate the factorization if a
diagonal element becomes smaller
than −tol.
iabort = 2 Terminate the factorization if the
absolute value of a diagonal element
becomes smaller than tol, that is.,
when a diagonal element is near zero.
iabort = 3 Do not terminate the factorization on
negative or near zero diagonal values.
This is the default if DSLEFF has not
been called.
fudge User specified value of the fudge factor, fudge > 0. Used
when iabort = 1 or iabort = 3. When a pivot that is
smaller in absolute value than tol is encountered in
DSLEFA or DSLECO, the near-zero pivot value is
replaced by fudge. The index of the first such pivot is
returned in non permuted order by the ier argument of
DSLEFA or DSLECO.