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

Chapter 15 Sparse Eigenvalues and Eigenvectors 1039
Eigenextraction DSEVEX
Output nfound The number of eigenvalues computed and confirmed to
meet the problem description constraints by inertia
(Sturm sequence) computations.
ndiscd The number of other eigenvalues computed during the
course of the computation but discarded because they
were outside of the specifications for eigenvalues or
because they were not confirmed by inertia
computations.
ier Status response:
ier = 0 Normal return.
ier < 0 Fatal error, no useful results returned.
ier > 0 Fatal error, but some eigenvalues and
vectors computed.
ier = −700 DSEVEX called without first
successfully calling earlier stages.
ier = ±701 Error in storage allocation.
ier = ±702 Illegal specification for lftend and
rhtend.
ier = ±703 Illegal specification for pbtype.
ier = ±704 Illegal specification for which.
ier = ±705 which = highest for an interval that
spans zero.
ier = ±706 Insufficient dynamic memory for
factorization.
ier = ±707 Internal error during factorization.
ier = ±709 Starting block I/O error.
ier = ±710 Factorization save error in finite
interval analysis.
ier = ±720 Error in storage allocation for first set
of Lanczos recurrence vectors.
ier = ±721 Error in storage allocation for second
set of Lanczos recurrence vectors.
ier = ±722 Error in storage allocation for
eigenvectors.
ier = ±723 Insufficient storage during Lanczos
iteration.
ier = ±724 QL iteration did not converge.