/* dggesx.f -- translated by f2c (version 20061008).
You must link the resulting object file with libf2c:
on Microsoft Windows system, link with libf2c.lib;
on Linux or Unix systems, link with .../path/to/libf2c.a -lm
or, if you install libf2c.a in a standard place, with -lf2c -lm
-- in that order, at the end of the command line, as in
cc *.o -lf2c -lm
Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
http://www.netlib.org/f2c/libf2c.zip
*/
#include "f2c.h"
#include "blaswrap.h"
/* Table of constant values */
static integer c__1 = 1;
static integer c__0 = 0;
static integer c_n1 = -1;
static doublereal c_b42 = 0.;
static doublereal c_b43 = 1.;
/* Subroutine */ int dggesx_(char *jobvsl, char *jobvsr, char *sort, L_fp
selctg, char *sense, integer *n, doublereal *a, integer *lda,
doublereal *b, integer *ldb, integer *sdim, doublereal *alphar,
doublereal *alphai, doublereal *beta, doublereal *vsl, integer *ldvsl,
doublereal *vsr, integer *ldvsr, doublereal *rconde, doublereal *
rcondv, doublereal *work, integer *lwork, integer *iwork, integer *
liwork, logical *bwork, integer *info)
{
/* System generated locals */
integer a_dim1, a_offset, b_dim1, b_offset, vsl_dim1, vsl_offset,
vsr_dim1, vsr_offset, i__1, i__2;
doublereal d__1;
/* Builtin functions */
double sqrt(doublereal);
/* Local variables */
integer i__, ip;
doublereal pl, pr, dif[2];
integer ihi, ilo;
doublereal eps;
integer ijob;
doublereal anrm, bnrm;
integer ierr, itau, iwrk, lwrk;
extern logical lsame_(char *, char *);
integer ileft, icols;
logical cursl, ilvsl, ilvsr;
integer irows;
extern /* Subroutine */ int dlabad_(doublereal *, doublereal *), dggbak_(
char *, char *, integer *, integer *, integer *, doublereal *,
doublereal *, integer *, doublereal *, integer *, integer *), dggbal_(char *, integer *, doublereal *, integer
*, doublereal *, integer *, integer *, integer *, doublereal *,
doublereal *, doublereal *, integer *);
logical lst2sl;
extern doublereal dlamch_(char *), dlange_(char *, integer *,
integer *, doublereal *, integer *, doublereal *);
extern /* Subroutine */ int dgghrd_(char *, char *, integer *, integer *,
integer *, doublereal *, integer *, doublereal *, integer *,
doublereal *, integer *, doublereal *, integer *, integer *), dlascl_(char *, integer *, integer *, doublereal
*, doublereal *, integer *, integer *, doublereal *, integer *,
integer *);
logical ilascl, ilbscl;
extern /* Subroutine */ int dgeqrf_(integer *, integer *, doublereal *,
integer *, doublereal *, doublereal *, integer *, integer *),
dlacpy_(char *, integer *, integer *, doublereal *, integer *,
doublereal *, integer *);
doublereal safmin;
extern /* Subroutine */ int dlaset_(char *, integer *, integer *,
doublereal *, doublereal *, doublereal *, integer *);
doublereal safmax;
extern /* Subroutine */ int xerbla_(char *, integer *);
doublereal bignum;
extern /* Subroutine */ int dhgeqz_(char *, char *, char *, integer *,
integer *, integer *, doublereal *, integer *, doublereal *,
integer *, doublereal *, doublereal *, doublereal *, doublereal *,
integer *, doublereal *, integer *, doublereal *, integer *,
integer *);
integer ijobvl, iright;
extern /* Subroutine */ int dtgsen_(integer *, logical *, logical *,
logical *, integer *, doublereal *, integer *, doublereal *,
integer *, doublereal *, doublereal *, doublereal *, doublereal *,
integer *, doublereal *, integer *, integer *, doublereal *,
doublereal *, doublereal *, doublereal *, integer *, integer *,
integer *, integer *);
extern integer ilaenv_(integer *, char *, char *, integer *, integer *,
integer *, integer *);
integer ijobvr;
logical wantsb;
integer liwmin;
logical wantse, lastsl;
doublereal anrmto, bnrmto;
extern /* Subroutine */ int dorgqr_(integer *, integer *, integer *,
doublereal *, integer *, doublereal *, doublereal *, integer *,
integer *);
integer minwrk, maxwrk;
logical wantsn;
doublereal smlnum;
extern /* Subroutine */ int dormqr_(char *, char *, integer *, integer *,
integer *, doublereal *, integer *, doublereal *, doublereal *,
integer *, doublereal *, integer *, integer *);
logical wantst, lquery, wantsv;
/* -- LAPACK driver routine (version 3.2) -- */
/* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/* November 2006 */
/* .. Scalar Arguments .. */
/* .. */
/* .. Array Arguments .. */
/* .. */
/* .. Function Arguments .. */
/* .. */
/* Purpose */
/* ======= */
/* DGGESX computes for a pair of N-by-N real nonsymmetric matrices */
/* (A,B), the generalized eigenvalues, the real Schur form (S,T), and, */
/* optionally, the left and/or right matrices of Schur vectors (VSL and */
/* VSR). This gives the generalized Schur factorization */
/* (A,B) = ( (VSL) S (VSR)**T, (VSL) T (VSR)**T ) */
/* Optionally, it also orders the eigenvalues so that a selected cluster */
/* of eigenvalues appears in the leading diagonal blocks of the upper */
/* quasi-triangular matrix S and the upper triangular matrix T; computes */
/* a reciprocal condition number for the average of the selected */
/* eigenvalues (RCONDE); and computes a reciprocal condition number for */
/* the right and left deflating subspaces corresponding to the selected */
/* eigenvalues (RCONDV). The leading columns of VSL and VSR then form */
/* an orthonormal basis for the corresponding left and right eigenspaces */
/* (deflating subspaces). */
/* A generalized eigenvalue for a pair of matrices (A,B) is 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 or for both being zero. */
/* A pair of matrices (S,T) is in generalized real Schur form if T is */
/* upper triangular with non-negative diagonal and S is block upper */
/* triangular with 1-by-1 and 2-by-2 blocks. 1-by-1 blocks correspond */
/* to real generalized eigenvalues, while 2-by-2 blocks of S will be */
/* "standardized" by making the corresponding elements of T have the */
/* form: */
/* [ a 0 ] */
/* [ 0 b ] */
/* and the pair of corresponding 2-by-2 blocks in S and T will have a */
/* complex conjugate pair of generalized eigenvalues. */
/* Arguments */
/* ========= */
/* JOBVSL (input) CHARACTER*1 */
/* = 'N': do not compute the left Schur vectors; */
/* = 'V': compute the left Schur vectors. */
/* JOBVSR (input) CHARACTER*1 */
/* = 'N': do not compute the right Schur vectors; */
/* = 'V': compute the right Schur vectors. */
/* SORT (input) CHARACTER*1 */
/* Specifies whether or not to order the eigenvalues on the */
/* diagonal of the generalized Schur form. */
/* = 'N': Eigenvalues are not ordered; */
/* = 'S': Eigenvalues are ordered (see SELCTG). */
/* SELCTG (external procedure) LOGICAL FUNCTION of three DOUBLE PRECISION arguments */
/* SELCTG must be declared EXTERNAL in the calling subroutine. */
/* If SORT = 'N', SELCTG is not referenced. */
/* If SORT = 'S', SELCTG is used to select eigenvalues to sort */
/* to the top left of the Schur form. */
/* An eigenvalue (ALPHAR(j)+ALPHAI(j))/BETA(j) is selected if */
/* SELCTG(ALPHAR(j),ALPHAI(j),BETA(j)) is true; i.e. if either */
/* one of a complex conjugate pair of eigenvalues is selected, */
/* then both complex eigenvalues are selected. */
/* Note that a selected complex eigenvalue may no longer satisfy */
/* SELCTG(ALPHAR(j),ALPHAI(j),BETA(j)) = .TRUE. after ordering, */
/* since ordering may change the value of complex eigenvalues */
/* (especially if the eigenvalue is ill-conditioned), in this */
/* case INFO is set to N+3. */
/* SENSE (input) CHARACTER*1 */
/* Determines which reciprocal condition numbers are computed. */
/* = 'N' : None are computed; */
/* = 'E' : Computed for average of selected eigenvalues only; */
/* = 'V' : Computed for selected deflating subspaces only; */
/* = 'B' : Computed for both. */
/* If SENSE = 'E', 'V', or 'B', SORT must equal 'S'. */
/* N (input) INTEGER */
/* The order of the matrices A, B, VSL, and VSR. N >= 0. */
/* A (input/output) DOUBLE PRECISION array, dimension (LDA, N) */
/* On entry, the first of the pair of matrices. */
/* On exit, A has been overwritten by its generalized Schur */
/* form S. */
/* LDA (input) INTEGER */
/* The leading dimension of A. LDA >= max(1,N). */
/* B (input/output) DOUBLE PRECISION array, dimension (LDB, N) */
/* On entry, the second of the pair of matrices. */
/* On exit, B has been overwritten by its generalized Schur */
/* form T. */
/* LDB (input) INTEGER */
/* The leading dimension of B. LDB >= max(1,N). */
/* SDIM (output) INTEGER */
/* If SORT = 'N', SDIM = 0. */
/* If SORT = 'S', SDIM = number of eigenvalues (after sorting) */
/* for which SELCTG is true. (Complex conjugate pairs for which */
/* SELCTG is true for either eigenvalue count as 2.) */
/* ALPHAR (output) DOUBLE PRECISION array, dimension (N) */
/* ALPHAI (output) DOUBLE PRECISION array, dimension (N) */
/* BETA (output) DOUBLE PRECISION array, dimension (N) */
/* On exit, (ALPHAR(j) + ALPHAI(j)*i)/BETA(j), j=1,...,N, will */
/* be the generalized eigenvalues. ALPHAR(j) + ALPHAI(j)*i */
/* and BETA(j),j=1,...,N are the diagonals of the complex Schur */
/* form (S,T) that would result if the 2-by-2 diagonal blocks of */
/* the real Schur form of (A,B) were further reduced to */
/* triangular form using 2-by-2 complex unitary transformations. */
/* If ALPHAI(j) is zero, then the j-th eigenvalue is real; if */
/* positive, then the j-th and (j+1)-st eigenvalues are a */
/* complex conjugate pair, with ALPHAI(j+1) negative. */
/* Note: the quotients ALPHAR(j)/BETA(j) and ALPHAI(j)/BETA(j) */
/* may easily over- or underflow, and BETA(j) may even be zero. */
/* Thus, the user should avoid naively computing the ratio. */
/* However, ALPHAR and ALPHAI will be always less than and */
/* usually comparable with norm(A) in magnitude, and BETA always */
/* less than and usually comparable with norm(B). */
/* VSL (output) DOUBLE PRECISION array, dimension (LDVSL,N) */
/* If JOBVSL = 'V', VSL will contain the left Schur vectors. */
/* Not referenced if JOBVSL = 'N'. */
/* LDVSL (input) INTEGER */
/* The leading dimension of the matrix VSL. LDVSL >=1, and */
/* if JOBVSL = 'V', LDVSL >= N. */
/* VSR (output) DOUBLE PRECISION array, dimension (LDVSR,N) */
/* If JOBVSR = 'V', VSR will contain the right Schur vectors. */
/* Not referenced if JOBVSR = 'N'. */
/* LDVSR (input) INTEGER */
/* The leading dimension of the matrix VSR. LDVSR >= 1, and */
/* if JOBVSR = 'V', LDVSR >= N. */
/* RCONDE (output) DOUBLE PRECISION array, dimension ( 2 ) */
/* If SENSE = 'E' or 'B', RCONDE(1) and RCONDE(2) contain the */
/* reciprocal condition numbers for the average of the selected */
/* eigenvalues. */
/* Not referenced if SENSE = 'N' or 'V'. */
/* RCONDV (output) DOUBLE PRECISION array, dimension ( 2 ) */
/* If SENSE = 'V' or 'B', RCONDV(1) and RCONDV(2) contain the */
/* reciprocal condition numbers for the selected deflating */
/* subspaces. */
/* Not referenced if SENSE = 'N' or 'E'. */
/* WORK (workspace/output) DOUBLE PRECISION array, dimension (MAX(1,LWORK)) */
/* On exit, if INFO = 0, WORK(1) returns the optimal LWORK. */
/* LWORK (input) INTEGER */
/* The dimension of the array WORK. */
/* If N = 0, LWORK >= 1, else if SENSE = 'E', 'V', or 'B', */
/* LWORK >= max( 8*N, 6*N+16, 2*SDIM*(N-SDIM) ), else */
/* LWORK >= max( 8*N, 6*N+16 ). */
/* Note that 2*SDIM*(N-SDIM) <= N*N/2. */
/* Note also that an error is only returned if */
/* LWORK < max( 8*N, 6*N+16), but if SENSE = 'E' or 'V' or 'B' */
/* this may not be large enough. */
/* If LWORK = -1, then a workspace query is assumed; the routine */
/* only calculates the bound on the optimal size of the WORK */
/* array and the minimum size of the IWORK array, returns these */
/* values as the first entries of the WORK and IWORK arrays, and */
/* no error message related to LWORK or LIWORK is issued by */
/* XERBLA. */
/* IWORK (workspace) INTEGER array, dimension (MAX(1,LIWORK)) */
/* On exit, if INFO = 0, IWORK(1) returns the minimum LIWORK. */
/* LIWORK (input) INTEGER */
/* The dimension of the array IWORK. */
/* If SENSE = 'N' or N = 0, LIWORK >= 1, otherwise */
/* LIWORK >= N+6. */
/* If LIWORK = -1, then a workspace query is assumed; the */
/* routine only calculates the bound on the optimal size of the */
/* WORK array and the minimum size of the IWORK array, returns */
/* these values as the first entries of the WORK and IWORK */
/* arrays, and no error message related to LWORK or LIWORK is */
/* issued by XERBLA. */
/* BWORK (workspace) LOGICAL array, dimension (N) */
/* Not referenced if SORT = 'N'. */
/* INFO (output) INTEGER */
/* = 0: successful exit */
/* < 0: if INFO = -i, the i-th argument had an illegal value. */
/* = 1,...,N: */
/* The QZ iteration failed. (A,B) are not in Schur */
/* form, but ALPHAR(j), ALPHAI(j), and BETA(j) should */
/* be correct for j=INFO+1,...,N. */
/* > N: =N+1: other than QZ iteration failed in DHGEQZ */
/* =N+2: after reordering, roundoff changed values of */
/* some complex eigenvalues so that leading */
/* eigenvalues in the Generalized Schur form no */
/* longer satisfy SELCTG=.TRUE. This could also */
/* be caused due to scaling. */
/* =N+3: reordering failed in DTGSEN. */
/* Further details */
/* =============== */
/* An approximate (asymptotic) bound on the average absolute error of */
/* the selected eigenvalues is */
/* EPS * norm((A, B)) / RCONDE( 1 ). */
/* An approximate (asymptotic) bound on the maximum angular error in */
/* the computed deflating subspaces is */
/* EPS * norm((A, B)) / RCONDV( 2 ). */
/* See LAPACK User's Guide, section 4.11 for more information. */
/* ===================================================================== */
/* .. Parameters .. */
/* .. */
/* .. Local Scalars .. */
/* .. */
/* .. Local Arrays .. */
/* .. */
/* .. External Subroutines .. */
/* .. */
/* .. External Functions .. */
/* .. */
/* .. Intrinsic Functions .. */
/* .. */
/* .. Executable Statements .. */
/* Decode the input arguments */
/* Parameter adjustments */
a_dim1 = *lda;
a_offset = 1 + a_dim1;
a -= a_offset;
b_dim1 = *ldb;
b_offset = 1 + b_dim1;
b -= b_offset;
--alphar;
--alphai;
--beta;
vsl_dim1 = *ldvsl;
vsl_offset = 1 + vsl_dim1;
vsl -= vsl_offset;
vsr_dim1 = *ldvsr;
vsr_offset = 1 + vsr_dim1;
vsr -= vsr_offset;
--rconde;
--rcondv;
--work;
--iwork;
--bwork;
/* Function Body */
if (lsame_(jobvsl, "N")) {
ijobvl = 1;
ilvsl = FALSE_;
} else if (lsame_(jobvsl, "V")) {
ijobvl = 2;
ilvsl = TRUE_;
} else {
ijobvl = -1;
ilvsl = FALSE_;
}
if (lsame_(jobvsr, "N")) {
ijobvr = 1;
ilvsr = FALSE_;
} else if (lsame_(jobvsr, "V")) {
ijobvr = 2;
ilvsr = TRUE_;
} else {
ijobvr = -1;
ilvsr = FALSE_;
}
wantst = lsame_(sort, "S");
wantsn = lsame_(sense, "N");
wantse = lsame_(sense, "E");
wantsv = lsame_(sense, "V");
wantsb = lsame_(sense, "B");
lquery = *lwork == -1 || *liwork == -1;
if (wantsn) {
ijob = 0;
} else if (wantse) {
ijob = 1;
} else if (wantsv) {
ijob = 2;
} else if (wantsb) {
ijob = 4;
}
/* Test the input arguments */
*info = 0;
if (ijobvl <= 0) {
*info = -1;
} else if (ijobvr <= 0) {
*info = -2;
} else if (! wantst && ! lsame_(sort, "N")) {
*info = -3;
} else if (! (wantsn || wantse || wantsv || wantsb) || ! wantst && !
wantsn) {
*info = -5;
} else if (*n < 0) {
*info = -6;
} else if (*lda < max(1,*n)) {
*info = -8;
} else if (*ldb < max(1,*n)) {
*info = -10;
} else if (*ldvsl < 1 || ilvsl && *ldvsl < *n) {
*info = -16;
} else if (*ldvsr < 1 || ilvsr && *ldvsr < *n) {
*info = -18;
}
/* Compute workspace */
/* (Note: Comments in the code beginning "Workspace:" describe the */
/* minimal amount of workspace needed at that point in the code, */
/* as well as the preferred amount for good performance. */
/* NB refers to the optimal block size for the immediately */
/* following subroutine, as returned by ILAENV.) */
if (*info == 0) {
if (*n > 0) {
/* Computing MAX */
i__1 = *n << 3, i__2 = *n * 6 + 16;
minwrk = max(i__1,i__2);
maxwrk = minwrk - *n + *n * ilaenv_(&c__1, "DGEQRF", " ", n, &
c__1, n, &c__0);
/* Computing MAX */
i__1 = maxwrk, i__2 = minwrk - *n + *n * ilaenv_(&c__1, "DORMQR",
" ", n, &c__1, n, &c_n1);
maxwrk = max(i__1,i__2);
if (ilvsl) {
/* Computing MAX */
i__1 = maxwrk, i__2 = minwrk - *n + *n * ilaenv_(&c__1, "DOR"
"GQR", " ", n, &c__1, n, &c_n1);
maxwrk = max(i__1,i__2);
}
lwrk = maxwrk;
if (ijob >= 1) {
/* Computing MAX */
i__1 = lwrk, i__2 = *n * *n / 2;
lwrk = max(i__1,i__2);
}
} else {
minwrk = 1;
maxwrk = 1;
lwrk = 1;
}
work[1] = (doublereal) lwrk;
if (wantsn || *n == 0) {
liwmin = 1;
} else {
liwmin = *n + 6;
}
iwork[1] = liwmin;
if (*lwork < minwrk && ! lquery) {
*info = -22;
} else if (*liwork < liwmin && ! lquery) {
*info = -24;
}
}
if (*info != 0) {
i__1 = -(*info);
xerbla_("DGGESX", &i__1);
return 0;
} else if (lquery) {
return 0;
}
/* Quick return if possible */
if (*n == 0) {
*sdim = 0;
return 0;
}
/* Get machine constants */
eps = dlamch_("P");
safmin = dlamch_("S");
safmax = 1. / safmin;
dlabad_(&safmin, &safmax);
smlnum = sqrt(safmin) / eps;
bignum = 1. / smlnum;
/* Scale A if max element outside range [SMLNUM,BIGNUM] */
anrm = dlange_("M", n, n, &a[a_offset], lda, &work[1]);
ilascl = FALSE_;
if (anrm > 0. && anrm < smlnum) {
anrmto = smlnum;
ilascl = TRUE_;
} else if (anrm > bignum) {
anrmto = bignum;
ilascl = TRUE_;
}
if (ilascl) {
dlascl_("G", &c__0, &c__0, &anrm, &anrmto, n, n, &a[a_offset], lda, &
ierr);
}
/* Scale B if max element outside range [SMLNUM,BIGNUM] */
bnrm = dlange_("M", n, n, &b[b_offset], ldb, &work[1]);
ilbscl = FALSE_;
if (bnrm > 0. && bnrm < smlnum) {
bnrmto = smlnum;
ilbscl = TRUE_;
} else if (bnrm > bignum) {
bnrmto = bignum;
ilbscl = TRUE_;
}
if (ilbscl) {
dlascl_("G", &c__0, &c__0, &bnrm, &bnrmto, n, n, &b[b_offset], ldb, &
ierr);
}
/* Permute the matrix to make it more nearly triangular */
/* (Workspace: need 6*N + 2*N for permutation parameters) */
ileft = 1;
iright = *n + 1;
iwrk = iright + *n;
dggbal_("P", n, &a[a_offset], lda, &b[b_offset], ldb, &ilo, &ihi, &work[
ileft], &work[iright], &work[iwrk], &ierr);
/* Reduce B to triangular form (QR decomposition of B) */
/* (Workspace: need N, prefer N*NB) */
irows = ihi + 1 - ilo;
icols = *n + 1 - ilo;
itau = iwrk;
iwrk = itau + irows;
i__1 = *lwork + 1 - iwrk;
dgeqrf_(&irows, &icols, &b[ilo + ilo * b_dim1], ldb, &work[itau], &work[
iwrk], &i__1, &ierr);
/* Apply the orthogonal transformation to matrix A */
/* (Workspace: need N, prefer N*NB) */
i__1 = *lwork + 1 - iwrk;
dormqr_("L", "T", &irows, &icols, &irows, &b[ilo + ilo * b_dim1], ldb, &
work[itau], &a[ilo + ilo * a_dim1], lda, &work[iwrk], &i__1, &
ierr);
/* Initialize VSL */
/* (Workspace: need N, prefer N*NB) */
if (ilvsl) {
dlaset_("Full", n, n, &c_b42, &c_b43, &vsl[vsl_offset], ldvsl);
if (irows > 1) {
i__1 = irows - 1;
i__2 = irows - 1;
dlacpy_("L", &i__1, &i__2, &b[ilo + 1 + ilo * b_dim1], ldb, &vsl[
ilo + 1 + ilo * vsl_dim1], ldvsl);
}
i__1 = *lwork + 1 - iwrk;
dorgqr_(&irows, &irows, &irows, &vsl[ilo + ilo * vsl_dim1], ldvsl, &
work[itau], &work[iwrk], &i__1, &ierr);
}
/* Initialize VSR */
if (ilvsr) {
dlaset_("Full", n, n, &c_b42, &c_b43, &vsr[vsr_offset], ldvsr);
}
/* Reduce to generalized Hessenberg form */
/* (Workspace: none needed) */
dgghrd_(jobvsl, jobvsr, n, &ilo, &ihi, &a[a_offset], lda, &b[b_offset],
ldb, &vsl[vsl_offset], ldvsl, &vsr[vsr_offset], ldvsr, &ierr);
*sdim = 0;
/* Perform QZ algorithm, computing Schur vectors if desired */
/* (Workspace: need N) */
iwrk = itau;
i__1 = *lwork + 1 - iwrk;
dhgeqz_("S", jobvsl, jobvsr, n, &ilo, &ihi, &a[a_offset], lda, &b[
b_offset], ldb, &alphar[1], &alphai[1], &beta[1], &vsl[vsl_offset]
, ldvsl, &vsr[vsr_offset], ldvsr, &work[iwrk], &i__1, &ierr);
if (ierr != 0) {
if (ierr > 0 && ierr <= *n) {
*info = ierr;
} else if (ierr > *n && ierr <= *n << 1) {
*info = ierr - *n;
} else {
*info = *n + 1;
}
goto L60;
}
/* Sort eigenvalues ALPHA/BETA and compute the reciprocal of */
/* condition number(s) */
/* (Workspace: If IJOB >= 1, need MAX( 8*(N+1), 2*SDIM*(N-SDIM) ) */
/* otherwise, need 8*(N+1) ) */
if (wantst) {
/* Undo scaling on eigenvalues before SELCTGing */
if (ilascl) {
dlascl_("G", &c__0, &c__0, &anrmto, &anrm, n, &c__1, &alphar[1],
n, &ierr);
dlascl_("G", &c__0, &c__0, &anrmto, &anrm, n, &c__1, &alphai[1],
n, &ierr);
}
if (ilbscl) {
dlascl_("G", &c__0, &c__0, &bnrmto, &bnrm, n, &c__1, &beta[1], n,
&ierr);
}
/* Select eigenvalues */
i__1 = *n;
for (i__ = 1; i__ <= i__1; ++i__) {
bwork[i__] = (*selctg)(&alphar[i__], &alphai[i__], &beta[i__]);
/* L10: */
}
/* Reorder eigenvalues, transform Generalized Schur vectors, and */
/* compute reciprocal condition numbers */
i__1 = *lwork - iwrk + 1;
dtgsen_(&ijob, &ilvsl, &ilvsr, &bwork[1], n, &a[a_offset], lda, &b[
b_offset], ldb, &alphar[1], &alphai[1], &beta[1], &vsl[
vsl_offset], ldvsl, &vsr[vsr_offset], ldvsr, sdim, &pl, &pr,
dif, &work[iwrk], &i__1, &iwork[1], liwork, &ierr);
if (ijob >= 1) {
/* Computing MAX */
i__1 = maxwrk, i__2 = (*sdim << 1) * (*n - *sdim);
maxwrk = max(i__1,i__2);
}
if (ierr == -22) {
/* not enough real workspace */
*info = -22;
} else {
if (ijob == 1 || ijob == 4) {
rconde[1] = pl;
rconde[2] = pr;
}
if (ijob == 2 || ijob == 4) {
rcondv[1] = dif[0];
rcondv[2] = dif[1];
}
if (ierr == 1) {
*info = *n + 3;
}
}
}
/* Apply permutation to VSL and VSR */
/* (Workspace: none needed) */
if (ilvsl) {
dggbak_("P", "L", n, &ilo, &ihi, &work[ileft], &work[iright], n, &vsl[
vsl_offset], ldvsl, &ierr);
}
if (ilvsr) {
dggbak_("P", "R", n, &ilo, &ihi, &work[ileft], &work[iright], n, &vsr[
vsr_offset], ldvsr, &ierr);
}
/* Check if unscaling would cause over/underflow, if so, rescale */
/* (ALPHAR(I),ALPHAI(I),BETA(I)) so BETA(I) is on the order of */
/* B(I,I) and ALPHAR(I) and ALPHAI(I) are on the order of A(I,I) */
if (ilascl) {
i__1 = *n;
for (i__ = 1; i__ <= i__1; ++i__) {
if (alphai[i__] != 0.) {
if (alphar[i__] / safmax > anrmto / anrm || safmin / alphar[
i__] > anrm / anrmto) {
work[1] = (d__1 = a[i__ + i__ * a_dim1] / alphar[i__],
abs(d__1));
beta[i__] *= work[1];
alphar[i__] *= work[1];
alphai[i__] *= work[1];
} else if (alphai[i__] / safmax > anrmto / anrm || safmin /
alphai[i__] > anrm / anrmto) {
work[1] = (d__1 = a[i__ + (i__ + 1) * a_dim1] / alphai[
i__], abs(d__1));
beta[i__] *= work[1];
alphar[i__] *= work[1];
alphai[i__] *= work[1];
}
}
/* L20: */
}
}
if (ilbscl) {
i__1 = *n;
for (i__ = 1; i__ <= i__1; ++i__) {
if (alphai[i__] != 0.) {
if (beta[i__] / safmax > bnrmto / bnrm || safmin / beta[i__]
> bnrm / bnrmto) {
work[1] = (d__1 = b[i__ + i__ * b_dim1] / beta[i__], abs(
d__1));
beta[i__] *= work[1];
alphar[i__] *= work[1];
alphai[i__] *= work[1];
}
}
/* L30: */
}
}
/* Undo scaling */
if (ilascl) {
dlascl_("H", &c__0, &c__0, &anrmto, &anrm, n, n, &a[a_offset], lda, &
ierr);
dlascl_("G", &c__0, &c__0, &anrmto, &anrm, n, &c__1, &alphar[1], n, &
ierr);
dlascl_("G", &c__0, &c__0, &anrmto, &anrm, n, &c__1, &alphai[1], n, &
ierr);
}
if (ilbscl) {
dlascl_("U", &c__0, &c__0, &bnrmto, &bnrm, n, n, &b[b_offset], ldb, &
ierr);
dlascl_("G", &c__0, &c__0, &bnrmto, &bnrm, n, &c__1, &beta[1], n, &
ierr);
}
if (wantst) {
/* Check if reordering is correct */
lastsl = TRUE_;
lst2sl = TRUE_;
*sdim = 0;
ip = 0;
i__1 = *n;
for (i__ = 1; i__ <= i__1; ++i__) {
cursl = (*selctg)(&alphar[i__], &alphai[i__], &beta[i__]);
if (alphai[i__] == 0.) {
if (cursl) {
++(*sdim);
}
ip = 0;
if (cursl && ! lastsl) {
*info = *n + 2;
}
} else {
if (ip == 1) {
/* Last eigenvalue of conjugate pair */
cursl = cursl || lastsl;
lastsl = cursl;
if (cursl) {
*sdim += 2;
}
ip = -1;
if (cursl && ! lst2sl) {
*info = *n + 2;
}
} else {
/* First eigenvalue of conjugate pair */
ip = 1;
}
}
lst2sl = lastsl;
lastsl = cursl;
/* L50: */
}
}
L60:
work[1] = (doublereal) maxwrk;
iwork[1] = liwmin;
return 0;
/* End of DGGESX */
} /* dggesx_ */
