SUBROUTINE CGEESX( JOBZ, SORTEV, SELECT, SENSE, N, A, LDA, NOUT, W, * Z, LDZ, RCONE, RCONV, WORK, LDWORK, WORK2, BWORK3, INFO) CHARACTER * 1 JOBZ, SORTEV, SENSE COMPLEX A(LDA,*), W(*), Z(LDZ,*), WORK(*) INTEGER N, LDA, NOUT, LDZ, LDWORK, INFO LOGICAL SELECT LOGICAL BWORK3(*) REAL RCONE, RCONV REAL WORK2(*) SUBROUTINE CGEESX_64( JOBZ, SORTEV, SELECT, SENSE, N, A, LDA, NOUT, * W, Z, LDZ, RCONE, RCONV, WORK, LDWORK, WORK2, BWORK3, INFO) CHARACTER * 1 JOBZ, SORTEV, SENSE COMPLEX A(LDA,*), W(*), Z(LDZ,*), WORK(*) INTEGER*8 N, LDA, NOUT, LDZ, LDWORK, INFO LOGICAL*8 SELECT LOGICAL*8 BWORK3(*) REAL RCONE, RCONV REAL WORK2(*)
SUBROUTINE GEESX( JOBZ, SORTEV, SELECT, SENSE, [N], A, [LDA], NOUT, * W, Z, [LDZ], RCONE, RCONV, [WORK], [LDWORK], [WORK2], [BWORK3], * [INFO]) CHARACTER(LEN=1) :: JOBZ, SORTEV, SENSE COMPLEX, DIMENSION(:) :: W, WORK COMPLEX, DIMENSION(:,:) :: A, Z INTEGER :: N, LDA, NOUT, LDZ, LDWORK, INFO LOGICAL :: SELECT LOGICAL, DIMENSION(:) :: BWORK3 REAL :: RCONE, RCONV REAL, DIMENSION(:) :: WORK2 SUBROUTINE GEESX_64( JOBZ, SORTEV, SELECT, SENSE, [N], A, [LDA], * NOUT, W, Z, [LDZ], RCONE, RCONV, [WORK], [LDWORK], [WORK2], * [BWORK3], [INFO]) CHARACTER(LEN=1) :: JOBZ, SORTEV, SENSE COMPLEX, DIMENSION(:) :: W, WORK COMPLEX, DIMENSION(:,:) :: A, Z INTEGER(8) :: N, LDA, NOUT, LDZ, LDWORK, INFO LOGICAL(8) :: SELECT LOGICAL(8), DIMENSION(:) :: BWORK3 REAL :: RCONE, RCONV REAL, DIMENSION(:) :: WORK2
void cgeesx(char jobz, char sortev, logical(*select)(complex), char sense, int n, complex *a, int lda, int *nout, complex *w, complex *z, int ldz, float *rcone, float *rconv, int *info);
void cgeesx_64(char jobz, char sortev, logical(*select)(complex), char sense, long n, complex *a, long lda, long *nout, complex *w, complex *z, long ldz, float *rcone, float *rconv, long *info);
Optionally, it also orders the eigenvalues on the diagonal of the Schur form so that selected eigenvalues are at the top left; computes a reciprocal condition number for the average of the selected eigenvalues (RCONDE); and computes a reciprocal condition number for the right invariant subspace corresponding to the selected eigenvalues (RCONDV). The leading columns of Z form an orthonormal basis for this invariant subspace.
For further explanation of the reciprocal condition numbers RCONDE and RCONDV, see Section 4.10 of the LAPACK Users' Guide (where these quantities are called s and sep respectively).
A complex matrix is in Schur form if it is upper triangular.