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Updated: June 2017
 
 

cggev (3p)

Name

cggev - N complex nonsymmetric matrices (A,B), the generalized eigenvalues, and optionally, the left and/or right generalized eigenvectors

Synopsis

SUBROUTINE CGGEV(JOBVL, JOBVR, N, A, LDA, B, LDB, ALPHA, BETA, VL,
LDVL, VR, LDVR, WORK, LWORK, RWORK, INFO)

CHARACTER*1 JOBVL, JOBVR
COMPLEX  A(LDA,*), B(LDB,*), ALPHA(*), BETA(*), VL(LDVL,*), VR(LDVR,*),
WORK(*)
INTEGER N, LDA, LDB, LDVL, LDVR, LWORK, INFO
REAL RWORK(*)

SUBROUTINE CGGEV_64(JOBVL, JOBVR, N, A, LDA, B, LDB, ALPHA, BETA, VL,
LDVL, VR, LDVR, WORK, LWORK, RWORK, INFO)

CHARACTER*1 JOBVL, JOBVR
COMPLEX A(LDA,*), B(LDB,*), ALPHA(*), BETA(*), VL(LDVL,*),  VR(LDVR,*),
WORK(*)
INTEGER*8 N, LDA, LDB, LDVL, LDVR, LWORK, INFO
REAL RWORK(*)




F95 INTERFACE
SUBROUTINE GGEV(JOBVL, JOBVR, N, A, LDA, B, LDB, ALPHA, BETA,
VL, LDVL, VR, LDVR, WORK, LWORK, RWORK, INFO)

CHARACTER(LEN=1) :: JOBVL, JOBVR
COMPLEX, DIMENSION(:) :: ALPHA, BETA, WORK
COMPLEX, DIMENSION(:,:) :: A, B, VL, VR
INTEGER :: N, LDA, LDB, LDVL, LDVR, LWORK, INFO
REAL, DIMENSION(:) :: RWORK

SUBROUTINE GGEV_64(JOBVL, JOBVR, N, A, LDA, B, LDB, ALPHA,
BETA, VL, LDVL, VR, LDVR, WORK, LWORK, RWORK, INFO)

CHARACTER(LEN=1) :: JOBVL, JOBVR
COMPLEX, DIMENSION(:) :: ALPHA, BETA, WORK
COMPLEX, DIMENSION(:,:) :: A, B, VL, VR
INTEGER(8) :: N, LDA, LDB, LDVL, LDVR, LWORK, INFO
REAL, DIMENSION(:) :: RWORK




C INTERFACE
#include <sunperf.h>

void  cggev(char jobvl, char jobvr, int n, complex *a, int lda, complex
*b, int ldb, complex *alpha, complex *beta, complex *vl,  int
ldvl, complex *vr, int ldvr, int *info);

void  cggev_64(char  jobvl,  char  jobvr, long n, complex *a, long lda,
complex *b, long ldb, complex *alpha, complex *beta,  complex
*vl, long ldvl, complex *vr, long ldvr, long *info);

Description

Oracle Solaris Studio Performance Library                            cggev(3P)



NAME
       cggev  -  compute  for  a  pair of N-by-N complex nonsymmetric matrices
       (A,B), the generalized eigenvalues, and  optionally,  the  left  and/or
       right generalized eigenvectors


SYNOPSIS
       SUBROUTINE CGGEV(JOBVL, JOBVR, N, A, LDA, B, LDB, ALPHA, BETA, VL,
             LDVL, VR, LDVR, WORK, LWORK, RWORK, INFO)

       CHARACTER*1 JOBVL, JOBVR
       COMPLEX  A(LDA,*), B(LDB,*), ALPHA(*), BETA(*), VL(LDVL,*), VR(LDVR,*),
       WORK(*)
       INTEGER N, LDA, LDB, LDVL, LDVR, LWORK, INFO
       REAL RWORK(*)

       SUBROUTINE CGGEV_64(JOBVL, JOBVR, N, A, LDA, B, LDB, ALPHA, BETA, VL,
             LDVL, VR, LDVR, WORK, LWORK, RWORK, INFO)

       CHARACTER*1 JOBVL, JOBVR
       COMPLEX A(LDA,*), B(LDB,*), ALPHA(*), BETA(*), VL(LDVL,*),  VR(LDVR,*),
       WORK(*)
       INTEGER*8 N, LDA, LDB, LDVL, LDVR, LWORK, INFO
       REAL RWORK(*)




   F95 INTERFACE
       SUBROUTINE GGEV(JOBVL, JOBVR, N, A, LDA, B, LDB, ALPHA, BETA,
              VL, LDVL, VR, LDVR, WORK, LWORK, RWORK, INFO)

       CHARACTER(LEN=1) :: JOBVL, JOBVR
       COMPLEX, DIMENSION(:) :: ALPHA, BETA, WORK
       COMPLEX, DIMENSION(:,:) :: A, B, VL, VR
       INTEGER :: N, LDA, LDB, LDVL, LDVR, LWORK, INFO
       REAL, DIMENSION(:) :: RWORK

       SUBROUTINE GGEV_64(JOBVL, JOBVR, N, A, LDA, B, LDB, ALPHA,
              BETA, VL, LDVL, VR, LDVR, WORK, LWORK, RWORK, INFO)

       CHARACTER(LEN=1) :: JOBVL, JOBVR
       COMPLEX, DIMENSION(:) :: ALPHA, BETA, WORK
       COMPLEX, DIMENSION(:,:) :: A, B, VL, VR
       INTEGER(8) :: N, LDA, LDB, LDVL, LDVR, LWORK, INFO
       REAL, DIMENSION(:) :: RWORK




   C INTERFACE
       #include <sunperf.h>

       void  cggev(char jobvl, char jobvr, int n, complex *a, int lda, complex
                 *b, int ldb, complex *alpha, complex *beta, complex *vl,  int
                 ldvl, complex *vr, int ldvr, int *info);

       void  cggev_64(char  jobvl,  char  jobvr, long n, complex *a, long lda,
                 complex *b, long ldb, complex *alpha, complex *beta,  complex
                 *vl, long ldvl, complex *vr, long ldvr, long *info);



PURPOSE
       cggev  computes  for  a  pair  of  N-by-N complex nonsymmetric matrices
       (A,B), the generalized eigenvalues, and  optionally,  the  left  and/or
       right generalized eigenvectors.

       A  generalized  eigenvalue  for  a  pair  of matrices (A,B) is a scalar
       lambda or a ratio alpha/beta = lambda, such that A - lambda*B is singu-
       lar.  It is usually represented as the pair (alpha,beta), as there is a
       reasonable interpretation for beta=0, and even for both being zero.

       The right generalized eigenvector v(j) corresponding to the generalized
       eigenvalue lambda(j) of (A,B) satisfies

                    A * v(j) = lambda(j) * B * v(j).

       The  left generalized eigenvector u(j) corresponding to the generalized
       eigenvalues lambda(j) of (A,B) satisfies

                    u(j)**H * A = lambda(j) * u(j)**H * B

       where u(j)**H is the conjugate-transpose of u(j).


ARGUMENTS
       JOBVL (input)
                 = 'N':  do not compute the left generalized eigenvectors;
                 = 'V':  compute the left generalized eigenvectors.


       JOBVR (input)
                 = 'N':  do not compute the right generalized eigenvectors;
                 = 'V':  compute the right generalized eigenvectors.


       N (input) The order of the matrices A, B, VL, and VR.  N >= 0.


       A (input/output)
                 On entry, the matrix A in the pair (A,B).   On  exit,  A  has
                 been overwritten.


       LDA (input)
                 The leading dimension of A.  LDA >= max(1,N).


       B (input/output)
                 On  entry,  the  matrix  B in the pair (A,B).  On exit, B has
                 been overwritten.


       LDB (input)
                 The leading dimension of B.  LDB >= max(1,N).


       ALPHA (output)
                 On exit, ALPHA(j)/BETA(j), j=1,...,N, will be the generalized
                 eigenvalues.

                 Note:  the  quotients  ALPHA(j)/BETA(j)  may  easily over- or
                 underflow, and BETA(j) may even  be  zero.   Thus,  the  user
                 should  avoid  naively  computing the ratio alpha/beta.  How-
                 ever, ALPHA will be always less than and  usually  comparable
                 with norm(A) in magnitude, and BETA always less than and usu-
                 ally comparable with norm(B).


       BETA (output)
                 See description of ALPHA.


       VL (output)
                 If JOBVL = 'V', the left generalized  eigenvectors  u(j)  are
                 stored  one  after  another in the columns of VL, in the same
                 order as their eigenvalues.  Each eigenvector will be  scaled
                 so the largest component will have abs(real part) + abs(imag.
                 part) = 1.  Not referenced if JOBVL = 'N'.


       LDVL (input)
                 The leading dimension of the matrix VL. LDVL  >=  1,  and  if
                 JOBVL = 'V', LDVL >= N.


       VR (output)
                 If  JOBVR  = 'V', the right generalized eigenvectors v(j) are
                 stored one after another in the columns of VR,  in  the  same
                 order  as their eigenvalues.  Each eigenvector will be scaled
                 so the largest component will have abs(real part) + abs(imag.
                 part) = 1.  Not referenced if JOBVR = 'N'.


       LDVR (input)
                 The  leading  dimension  of  the matrix VR. LDVR >= 1, and if
                 JOBVR = 'V', LDVR >= N.


       WORK (workspace)
                 On exit, if INFO = 0, WORK(1) returns the optimal LWORK.


       LWORK (input)
                 The dimension of the array WORK.  LWORK >=  max(1,2*N).   For
                 good performance, LWORK must generally be larger.

                 If LWORK = -1, then a workspace query is assumed; the routine
                 only calculates the optimal size of the WORK  array,  returns
                 this value as the first entry of the WORK array, and no error
                 message related to LWORK is issued by XERBLA.


       RWORK (workspace)
                 dimension(8*N)

       INFO (output)
                 = 0:  successful exit
                 < 0:  if INFO = -i, the i-th argument had an illegal value.
                 =1,...,N: The QZ iteration failed.  No eigenvectors have been
                 calculated,  but  ALPHA(j)  and BETA(j) should be correct for
                 j=INFO+1,...,N.  > N:  =N+1: other then QZ  iteration  failed
                 in SHGEQZ,
                 =N+2: error return from STGEVC.




                                  7 Nov 2015                         cggev(3P)