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

892 HP MLIB User’s Guide
DSLECO Numeric factorization and condition number estimation
INTEGER*8 inrtia(3), ier
REAL*8 pvttol, rcond
REAL*8 global(150)
CALL DSLECO(pvttol, rcond, inrtia, global, ier)
INTEGER*8 inrtia(3), ier
REAL*16 pvttol, rcond
REAL*8 global(150)
CALL QSLECO(pvttol, rcond, inrtia, global, ier)
INTEGER*8 inrtia(3), ier
COMPLEX*8 pvttol, rcond
REAL*8 global(150)
CALL CSLECO(pvttol, rcond, inrtia, global, ier)
INTEGER*8 inrtia(3), ier
COMPLEX*16 pvttol, rcond
REAL*8 global(150)
CALL ZSLECO(pvttol, rcond, inrtia, global, ier)
Input pvttol Pivoting tolerance; 0 ≤ pvttol ≤ 1. The value 0 gives a
reordering that minimizes fill; this value is appropriate
for positive definite matrices and provides the greatest
efficiency. The value 1 gives the best guarantee of
numerical stability for problems not known to be
positive definite.
pvttol is not used in the unsymmetric case.
Updated global Global communications array for this problem. This
array must be passed, untouched by the user, to
successive subroutines in this package.
Output rcond Estimate of the reciprocal of the 1-norm condition
number.
inrtia Array of length 3 containing, respectively, the number
of positive eigenvalues, the number of negative
eigenvalues, and an indicator if there are zero
eigenvalues.
ier Status response:
ier = 0 Normal return.
ier = −500 Incorrect processing path; value
input not performed.