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

Chapter 15 Sparse Eigenvalues and Eigenvectors 1025
One-call usage DSEVE1
pbtype Character string indicating type of problem. Only the
first character is significant, but longer input can be
used for clarity (for example, ’Vibration’ or ’Ordinary’).
’V’ or ’v’ Generalized symmetric (vibration)
problem Kx = λMx, with M positive
semi-definite.
’B’ or ’b’ Generalized symmetric (buckling)
problem Kx = λK
δ
x, with K positive
semi definite and K
δ
possibly
indefinite.
’O’ or ’o’ Ordinary symmetric eigenproblem
Kx = λx.
lfinit If .TRUE., the value of the argument lftend is to be
used as a restriction on the location of computed
eigenvalues. If .FALSE., no lower bound is placed on
the value of computed eigenvalues; equivalently, the
left endpoint is negative infinity.
lftend Left endpoint of an interval in which the desired
eigenvalues lie; not used if lfinit is .FALSE.
rfinit If .TRUE., the value of the argument rhtend is to be
used as a restriction on the location of computed
eigenvalues. If .FALSE., no upper bound is placed on
the value of computed eigenvalues; equivalently, the
right endpoint is positive infinity.
rhtend Right endpoint of an interval in which the desired
eigenvalues lie; not used if rfinit is .FALSE.
center A center or critical value for use when eigenvalues
nearest some particular value are desired. Referenced
only when which specifies ’centered’ or ’nearest’.
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.