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## Arguments

A
(input/output) REAL or COMPLEX square array, shape .
On entry, the matrix .
On exit, the matrix .

B
(input/output) REAL or COMPLEX square array, shape with .
On entry, the matrix .
On exit, the matrix .

alpha
(output) REAL or COMPLEX array, shape with .
The values of . ::= ALPHAR(:), ALPHAI(:) ALPHA(:),
where
ALPHAR(:), ALPHAI(:) are of REAL type (for the real and imaginary parts) and ALPHA(:) is of COMPLEX type.

BETA
(output) REAL or COMPLEX array, shape with .
The values of .
Note: The generalized eigenvalues of the pair are the scalars . These quotients may easily over- or underflow, and may even be zero. Thus, the user should avoid computing them naively.
Note: If A and B are real then complex eigenvalues occur in complex conjugate pairs. Each pair is stored consecutively. Thus a complex conjugate pair is given by where VSL
Optional (output) REAL or COMPLEX square array, shape with (VSL,1) (A,1).
The left Schur vectors.

VSR
Optional (output) REAL or COMPLEX square array, shape with (VSR,1) (A,1).
The right Schur vectors.

SELECT
Optional (input) LOGICAL FUNCTION
LOGICAL FUNCTION SELECT( alpha , BETA )
type(wp), INTENT(IN) :: alpha , BETA where
type ::= REAL COMPLEX
wp ::= KIND(1.0) KIND(1.0D0)
alpha ::= ALPHAR , ALPHAI  ALPHA  Note: Select must be present if SDIM, RCONDE and RCONDF are desired.

SDIM
Optional (output) INTEGER.
The number of eigenvalues (after sorting) for which SELECT .TRUE. (If and are real, complex conjugate pairs for which SELECT .TRUE. for either eigenvalue count as 2).

RCONDE
Optional (output) REAL array, shape with (RCONDE) .
The reciprocal condition numbers for the average of the selected eigenvalues.

RCONDV
Optional (output) REAL array, shape with (RCONDV) .
The reciprocal condition numbers for the left and right deflating subspaces corresponding to the selected eigenvalues.

INFO
Optional (output) INTEGER. If INFO is not present and an error occurs, then the program is terminated with an error message.
References:  and [17,9,20,21].     Next: Example (from Program LA_GGESX_EXAMPLE) Up: Generalized Nonsymmetric Eigenvalue Problems Previous: Purpose   Contents   Index
Susan Blackford 2001-08-19