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Updated: June 2017
 
 

cgegv (3p)

Name

cgegv - routine is deprecated and has been replaced by routine CGGEV

Synopsis

SUBROUTINE CGEGV(JOBVL, JOBVR, N, A, LDA, B, LDB, ALPHA, BETA, VL,
LDVL, VR, LDVR, WORK, LDWORK, WORK2, INFO)

CHARACTER*1 JOBVL, JOBVR
COMPLEX  A(LDA,*), B(LDB,*), ALPHA(*), BETA(*), VL(LDVL,*), VR(LDVR,*),
WORK(*)
INTEGER N, LDA, LDB, LDVL, LDVR, LDWORK, INFO
REAL WORK2(*)

SUBROUTINE CGEGV_64(JOBVL, JOBVR, N, A, LDA, B, LDB, ALPHA, BETA, VL,
LDVL, VR, LDVR, WORK, LDWORK, WORK2, INFO)

CHARACTER*1 JOBVL, JOBVR
COMPLEX A(LDA,*), B(LDB,*), ALPHA(*), BETA(*), VL(LDVL,*),  VR(LDVR,*),
WORK(*)
INTEGER*8 N, LDA, LDB, LDVL, LDVR, LDWORK, INFO
REAL WORK2(*)




F95 INTERFACE
SUBROUTINE GEGV(JOBVL, JOBVR, N, A, LDA, B, LDB, ALPHA, BETA,
VL, LDVL, VR, LDVR, WORK, LDWORK, WORK2, INFO)

CHARACTER(LEN=1) :: JOBVL, JOBVR
COMPLEX, DIMENSION(:) :: ALPHA, BETA, WORK
COMPLEX, DIMENSION(:,:) :: A, B, VL, VR
INTEGER :: N, LDA, LDB, LDVL, LDVR, LDWORK, INFO
REAL, DIMENSION(:) :: WORK2

SUBROUTINE GEGV_64(JOBVL, JOBVR, N, A, LDA, B, LDB, ALPHA,
BETA, VL, LDVL, VR, LDVR, WORK, LDWORK, WORK2, INFO)

CHARACTER(LEN=1) :: JOBVL, JOBVR
COMPLEX, DIMENSION(:) :: ALPHA, BETA, WORK
COMPLEX, DIMENSION(:,:) :: A, B, VL, VR
INTEGER(8) :: N, LDA, LDB, LDVL, LDVR, LDWORK, INFO
REAL, DIMENSION(:) :: WORK2




C INTERFACE
#include <sunperf.h>

void  cgegv(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  cgegv_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                            cgegv(3P)



NAME
       cgegv - routine is deprecated and has been replaced by routine CGGEV


SYNOPSIS
       SUBROUTINE CGEGV(JOBVL, JOBVR, N, A, LDA, B, LDB, ALPHA, BETA, VL,
             LDVL, VR, LDVR, WORK, LDWORK, WORK2, INFO)

       CHARACTER*1 JOBVL, JOBVR
       COMPLEX  A(LDA,*), B(LDB,*), ALPHA(*), BETA(*), VL(LDVL,*), VR(LDVR,*),
       WORK(*)
       INTEGER N, LDA, LDB, LDVL, LDVR, LDWORK, INFO
       REAL WORK2(*)

       SUBROUTINE CGEGV_64(JOBVL, JOBVR, N, A, LDA, B, LDB, ALPHA, BETA, VL,
             LDVL, VR, LDVR, WORK, LDWORK, WORK2, INFO)

       CHARACTER*1 JOBVL, JOBVR
       COMPLEX A(LDA,*), B(LDB,*), ALPHA(*), BETA(*), VL(LDVL,*),  VR(LDVR,*),
       WORK(*)
       INTEGER*8 N, LDA, LDB, LDVL, LDVR, LDWORK, INFO
       REAL WORK2(*)




   F95 INTERFACE
       SUBROUTINE GEGV(JOBVL, JOBVR, N, A, LDA, B, LDB, ALPHA, BETA,
              VL, LDVL, VR, LDVR, WORK, LDWORK, WORK2, INFO)

       CHARACTER(LEN=1) :: JOBVL, JOBVR
       COMPLEX, DIMENSION(:) :: ALPHA, BETA, WORK
       COMPLEX, DIMENSION(:,:) :: A, B, VL, VR
       INTEGER :: N, LDA, LDB, LDVL, LDVR, LDWORK, INFO
       REAL, DIMENSION(:) :: WORK2

       SUBROUTINE GEGV_64(JOBVL, JOBVR, N, A, LDA, B, LDB, ALPHA,
              BETA, VL, LDVL, VR, LDVR, WORK, LDWORK, WORK2, INFO)

       CHARACTER(LEN=1) :: JOBVL, JOBVR
       COMPLEX, DIMENSION(:) :: ALPHA, BETA, WORK
       COMPLEX, DIMENSION(:,:) :: A, B, VL, VR
       INTEGER(8) :: N, LDA, LDB, LDVL, LDVR, LDWORK, INFO
       REAL, DIMENSION(:) :: WORK2




   C INTERFACE
       #include <sunperf.h>

       void  cgegv(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  cgegv_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
       cgegv routine is deprecated and has been replaced by routine CGGEV.

       CGEGV computes for a pair of N-by-N complex nonsymmetric matrices A and
       B, the generalized eigenvalues (alpha, beta), and optionally, the  left
       and/or right generalized eigenvectors (VL and VR).

       A  generalized  eigenvalue  for  a  pair  of matrices (A,B) is, roughly
       speaking, a scalar w or a ratio  alpha/beta = w, such that  A - w*B  is
       singular.  It is usually represented as the pair (alpha,beta), as there
       is a reasonable interpretation for beta=0,  and  even  for  both  being
       zero.   A  good beginning reference is the book, "Matrix Computations",
       by G. Golub & C. van Loan (Johns Hopkins U. Press)

       A right generalized eigenvector corresponding to a  generalized  eigen-
       value   w  for a pair of matrices (A,B) is a vector  r  such that  (A -
       w B) r = 0 .  A left generalized eigenvector is a vector  l  such  that
       l**H * (A - w B) = 0, where l**H is the
       conjugate-transpose of l.

       Note:  this routine performs "full balancing" on A and B.  See "Further
       Details", below.


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 first of the pair of matrices whose generalized
                 eigenvalues  and (optionally) generalized eigenvectors are to
                 be computed.  On exit, the contents will have been destroyed.
                 (For a description of the contents of A on exit, see "Further
                 Details", below.)


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


       B (input/output)
                 On entry, the second of the pair of matrices  whose  general-
                 ized  eigenvalues  and  (optionally) generalized eigenvectors
                 are to be computed.  On exit, the  contents  will  have  been
                 destroyed.   (For a description of the contents of B on exit,
                 see "Further Details", below.)


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


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

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


       VL (output)
                 If JOBVL = 'V',  the  left  generalized  eigenvectors.   (See
                 "Purpose",  above.)   Each  eigenvector will be scaled so the
                 largest component will have abs(real part) + abs(imag.  part)
                 =  1, *except* that for eigenvalues with alpha=beta=0, a zero
                 vector will be returned  as  the  corresponding  eigenvector.
                 Not referenced if JOBVL = 'N'.


       BETA (output)
                 If  JOBVL  =  'V',  the  left generalized eigenvectors.  (See
                 "Purpose", above.)  Each eigenvector will be  scaled  so  the
                 largest  component will have abs(real part) + abs(imag. part)
                 = 1, *except* that for eigenvalues with alpha=beta=0, a  zero
                 vector  will  be  returned  as the corresponding eigenvector.
                 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.  (See
                 "Purpose", above.)  Each eigenvector will be  scaled  so  the
                 largest  component will have abs(real part) + abs(imag. part)
                 = 1, *except* that for eigenvalues with alpha=beta=0, a  zero
                 vector  will  be  returned  as the corresponding eigenvector.
                 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 LDWORK.


       LDWORK (input)
                 The  dimension of the array WORK.  LDWORK >= max(1,2*N).  For
                 good performance, LDWORK must generally be larger.   To  com-
                 pute  the  optimal value of LDWORK, call ILAENV to get block-
                 sizes (for CGEQRF, CUNMQR, and CUNGQR.)  Then compute: NB  as
                 the MAX of the blocksizes for CGEQRF, CUNMQR, and CUNGQR; The
                 optimal LDWORK is  MAX( 2*N, N*(NB+1) ).

                 If LDWORK = -1, then a workspace query is assumed;  the  rou-
                 tine  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 LDWORK is issued by XERBLA.


       WORK2 (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  VL(j)  should  be  correct  for
                 j=INFO+1,...,N.   >  N:   errors that usually indicate LAPACK
                 problems:
                 =N+1: error return from CGGBAL
                 =N+2: error return from CGEQRF
                 =N+3: error return from CUNMQR
                 =N+4: error return from CUNGQR
                 =N+5: error return from CGGHRD
                 =N+6: error return from CHGEQZ (other than failed  iteration)
                 =N+7: error return from CTGEVC
                 =N+8: error return from CGGBAK (computing VL)
                 =N+9: error return from CGGBAK (computing VR)
                 =N+10: error return from CLASCL (various calls)

FURTHER DETAILS
       Balancing
       ---------

       This  driver calls CGGBAL to both permute and scale rows and columns of
       A and B.  The permutations PL and PR are chosen  so  that  PL*A*PR  and
       PL*B*R  will  be  upper  triangular  except  for  the  diagonal  blocks
       A(i:j,i:j) and B(i:j,i:j), with i and j as close together as  possible.
       The  diagonal  scaling  matrices  DL and DR are chosen so that the pair
       DL*PL*A*PR*DR, DL*PL*B*PR*DR have elements close to one (except for the
       elements that start out zero.)

       After  the  eigenvalues  and eigenvectors of the balanced matrices have
       been computed, CGGBAK transforms the eigenvectors  back  to  what  they
       would  have been (in perfect arithmetic) if they had not been balanced.

       Contents of A and B on Exit
       -------- -- - --- - -- ----

       If any eigenvectors are computed  (either  JOBVL='V'  or  JOBVR='V'  or
       both),  then  on exit the arrays A and B will contain the complex Schur
       form[*] of the "balanced" versions of A and B.  If no eigenvectors  are
       computed, then only the diagonal blocks will be correct.

       [*] In other words, upper triangular form.




                                  7 Nov 2015                         cgegv(3P)