Exemple #1
0
/* Subroutine */ int dgees_(char *jobvs, char *sort, L_fp select, integer *n,
                            doublereal *a, integer *lda, integer *sdim, doublereal *wr,
                            doublereal *wi, doublereal *vs, integer *ldvs, doublereal *work,
                            integer *lwork, logical *bwork, integer *info)
{
    /* System generated locals */
    integer a_dim1, a_offset, vs_dim1, vs_offset, i__1, i__2, i__3;

    /* Builtin functions */
    double sqrt(doublereal);

    /* Local variables */
    integer i__;
    doublereal s;
    integer i1, i2, ip, ihi, ilo;
    doublereal dum[1], eps, sep;
    integer ibal;
    doublereal anrm;
    integer idum[1], ierr, itau, iwrk, inxt, icond, ieval;
    extern logical lsame_(char *, char *);
    extern /* Subroutine */ int dcopy_(integer *, doublereal *, integer *,
                                       doublereal *, integer *), dswap_(integer *, doublereal *, integer
                                               *, doublereal *, integer *);
    logical cursl;
    extern /* Subroutine */ int dlabad_(doublereal *, doublereal *), dgebak_(
        char *, char *, integer *, integer *, integer *, doublereal *,
        integer *, doublereal *, integer *, integer *),
                dgebal_(char *, integer *, doublereal *, integer *, integer *,
                        integer *, doublereal *, integer *);
    logical lst2sl, scalea;
    extern doublereal dlamch_(char *);
    doublereal cscale;
    extern doublereal dlange_(char *, integer *, integer *, doublereal *,
                              integer *, doublereal *);
    extern /* Subroutine */ int dgehrd_(integer *, integer *, integer *,
                                        doublereal *, integer *, doublereal *, doublereal *, integer *,
                                        integer *), dlascl_(char *, integer *, integer *, doublereal *,
                                                doublereal *, integer *, integer *, doublereal *, integer *,
                                                integer *), dlacpy_(char *, integer *, integer *,
                                                        doublereal *, integer *, doublereal *, integer *),
                                                                   xerbla_(char *, integer *);
    extern integer ilaenv_(integer *, char *, char *, integer *, integer *,
                           integer *, integer *);
    doublereal bignum;
    extern /* Subroutine */ int dorghr_(integer *, integer *, integer *,
                                        doublereal *, integer *, doublereal *, doublereal *, integer *,
                                        integer *), dhseqr_(char *, char *, integer *, integer *, integer
                                                *, doublereal *, integer *, doublereal *, doublereal *,
                                                doublereal *, integer *, doublereal *, integer *, integer *), dtrsen_(char *, char *, logical *, integer *,
                                                        doublereal *, integer *, doublereal *, integer *, doublereal *,
                                                        doublereal *, integer *, doublereal *, doublereal *, doublereal *,
                                                        integer *, integer *, integer *, integer *);
    logical lastsl;
    integer minwrk, maxwrk;
    doublereal smlnum;
    integer hswork;
    logical wantst, lquery, wantvs;


    /*  -- LAPACK driver routine (version 3.1) -- */
    /*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
    /*     November 2006 */

    /*     .. Scalar Arguments .. */
    /*     .. */
    /*     .. Array Arguments .. */
    /*     .. */
    /*     .. Function Arguments .. */
    /*     .. */

    /*  Purpose */
    /*  ======= */

    /*  DGEES computes for an N-by-N real nonsymmetric matrix A, the */
    /*  eigenvalues, the real Schur form T, and, optionally, the matrix of */
    /*  Schur vectors Z.  This gives the Schur factorization A = Z*T*(Z**T). */

    /*  Optionally, it also orders the eigenvalues on the diagonal of the */
    /*  real Schur form so that selected eigenvalues are at the top left. */
    /*  The leading columns of Z then form an orthonormal basis for the */
    /*  invariant subspace corresponding to the selected eigenvalues. */

    /*  A matrix is in real Schur form if it is upper quasi-triangular with */
    /*  1-by-1 and 2-by-2 blocks. 2-by-2 blocks will be standardized in the */
    /*  form */
    /*          [  a  b  ] */
    /*          [  c  a  ] */

    /*  where b*c < 0. The eigenvalues of such a block are a +- sqrt(bc). */

    /*  Arguments */
    /*  ========= */

    /*  JOBVS   (input) CHARACTER*1 */
    /*          = 'N': Schur vectors are not computed; */
    /*          = 'V': Schur vectors are computed. */

    /*  SORT    (input) CHARACTER*1 */
    /*          Specifies whether or not to order the eigenvalues on the */
    /*          diagonal of the Schur form. */
    /*          = 'N': Eigenvalues are not ordered; */
    /*          = 'S': Eigenvalues are ordered (see SELECT). */

    /*  SELECT  (external procedure) LOGICAL FUNCTION of two DOUBLE PRECISION arguments */
    /*          SELECT must be declared EXTERNAL in the calling subroutine. */
    /*          If SORT = 'S', SELECT is used to select eigenvalues to sort */
    /*          to the top left of the Schur form. */
    /*          If SORT = 'N', SELECT is not referenced. */
    /*          An eigenvalue WR(j)+sqrt(-1)*WI(j) is selected if */
    /*          SELECT(WR(j),WI(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 SELECT(WR(j),WI(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+2 (see INFO below). */

    /*  N       (input) INTEGER */
    /*          The order of the matrix A. N >= 0. */

    /*  A       (input/output) DOUBLE PRECISION array, dimension (LDA,N) */
    /*          On entry, the N-by-N matrix A. */
    /*          On exit, A has been overwritten by its real Schur form T. */

    /*  LDA     (input) INTEGER */
    /*          The leading dimension of the array A.  LDA >= max(1,N). */

    /*  SDIM    (output) INTEGER */
    /*          If SORT = 'N', SDIM = 0. */
    /*          If SORT = 'S', SDIM = number of eigenvalues (after sorting) */
    /*                         for which SELECT is true. (Complex conjugate */
    /*                         pairs for which SELECT is true for either */
    /*                         eigenvalue count as 2.) */

    /*  WR      (output) DOUBLE PRECISION array, dimension (N) */
    /*  WI      (output) DOUBLE PRECISION array, dimension (N) */
    /*          WR and WI contain the real and imaginary parts, */
    /*          respectively, of the computed eigenvalues in the same order */
    /*          that they appear on the diagonal of the output Schur form T. */
    /*          Complex conjugate pairs of eigenvalues will appear */
    /*          consecutively with the eigenvalue having the positive */
    /*          imaginary part first. */

    /*  VS      (output) DOUBLE PRECISION array, dimension (LDVS,N) */
    /*          If JOBVS = 'V', VS contains the orthogonal matrix Z of Schur */
    /*          vectors. */
    /*          If JOBVS = 'N', VS is not referenced. */

    /*  LDVS    (input) INTEGER */
    /*          The leading dimension of the array VS.  LDVS >= 1; if */
    /*          JOBVS = 'V', LDVS >= N. */

    /*  WORK    (workspace/output) DOUBLE PRECISION array, dimension (MAX(1,LWORK)) */
    /*          On exit, if INFO = 0, WORK(1) contains the optimal LWORK. */

    /*  LWORK   (input) INTEGER */
    /*          The dimension of the array WORK.  LWORK >= max(1,3*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. */

    /*  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. */
    /*          > 0: if INFO = i, and i is */
    /*             <= N: the QR algorithm failed to compute all the */
    /*                   eigenvalues; elements 1:ILO-1 and i+1:N of WR and WI */
    /*                   contain those eigenvalues which have converged; if */
    /*                   JOBVS = 'V', VS contains the matrix which reduces A */
    /*                   to its partially converged Schur form. */
    /*             = N+1: the eigenvalues could not be reordered because some */
    /*                   eigenvalues were too close to separate (the problem */
    /*                   is very ill-conditioned); */
    /*             = N+2: after reordering, roundoff changed values of some */
    /*                   complex eigenvalues so that leading eigenvalues in */
    /*                   the Schur form no longer satisfy SELECT=.TRUE.  This */
    /*                   could also be caused by underflow due to scaling. */

    /*  ===================================================================== */

    /*     .. Parameters .. */
    /*     .. */
    /*     .. Local Scalars .. */
    /*     .. */
    /*     .. Local Arrays .. */
    /*     .. */
    /*     .. External Subroutines .. */
    /*     .. */
    /*     .. External Functions .. */
    /*     .. */
    /*     .. Intrinsic Functions .. */
    /*     .. */
    /*     .. Executable Statements .. */

    /*     Test the input arguments */

    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --wr;
    --wi;
    vs_dim1 = *ldvs;
    vs_offset = 1 + vs_dim1;
    vs -= vs_offset;
    --work;
    --bwork;

    /* Function Body */
    *info = 0;
    lquery = *lwork == -1;
    wantvs = lsame_(jobvs, "V");
    wantst = lsame_(sort, "S");
    if (! wantvs && ! lsame_(jobvs, "N")) {
        *info = -1;
    } else if (! wantst && ! lsame_(sort, "N")) {
        *info = -2;
    } else if (*n < 0) {
        *info = -4;
    } else if (*lda < max(1,*n)) {
        *info = -6;
    } else if (*ldvs < 1 || wantvs && *ldvs < *n) {
        *info = -11;
    }

    /*     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. */
    /*       HSWORK refers to the workspace preferred by DHSEQR, as */
    /*       calculated below. HSWORK is computed assuming ILO=1 and IHI=N, */
    /*       the worst case.) */

    if (*info == 0) {
        if (*n == 0) {
            minwrk = 1;
            maxwrk = 1;
        } else {
            maxwrk = (*n << 1) + *n * ilaenv_(&c__1, "DGEHRD", " ", n, &c__1,
                                              n, &c__0);
            minwrk = *n * 3;

            dhseqr_("S", jobvs, n, &c__1, n, &a[a_offset], lda, &wr[1], &wi[1]
                    , &vs[vs_offset], ldvs, &work[1], &c_n1, &ieval);
            hswork = (integer) work[1];

            if (! wantvs) {
                /* Computing MAX */
                i__1 = maxwrk, i__2 = *n + hswork;
                maxwrk = max(i__1,i__2);
            } else {
                /* Computing MAX */
                i__1 = maxwrk, i__2 = (*n << 1) + (*n - 1) * ilaenv_(&c__1,
                                      "DORGHR", " ", n, &c__1, n, &c_n1);
                maxwrk = max(i__1,i__2);
                /* Computing MAX */
                i__1 = maxwrk, i__2 = *n + hswork;
                maxwrk = max(i__1,i__2);
            }
        }
        work[1] = (doublereal) maxwrk;

        if (*lwork < minwrk && ! lquery) {
            *info = -13;
        }
    }

    if (*info != 0) {
        i__1 = -(*info);
        xerbla_("DGEES ", &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");
    smlnum = dlamch_("S");
    bignum = 1. / smlnum;
    dlabad_(&smlnum, &bignum);
    smlnum = sqrt(smlnum) / eps;
    bignum = 1. / smlnum;

    /*     Scale A if max element outside range [SMLNUM,BIGNUM] */

    anrm = dlange_("M", n, n, &a[a_offset], lda, dum);
    scalea = FALSE_;
    if (anrm > 0. && anrm < smlnum) {
        scalea = TRUE_;
        cscale = smlnum;
    } else if (anrm > bignum) {
        scalea = TRUE_;
        cscale = bignum;
    }
    if (scalea) {
        dlascl_("G", &c__0, &c__0, &anrm, &cscale, n, n, &a[a_offset], lda, &
                ierr);
    }

    /*     Permute the matrix to make it more nearly triangular */
    /*     (Workspace: need N) */

    ibal = 1;
    dgebal_("P", n, &a[a_offset], lda, &ilo, &ihi, &work[ibal], &ierr);

    /*     Reduce to upper Hessenberg form */
    /*     (Workspace: need 3*N, prefer 2*N+N*NB) */

    itau = *n + ibal;
    iwrk = *n + itau;
    i__1 = *lwork - iwrk + 1;
    dgehrd_(n, &ilo, &ihi, &a[a_offset], lda, &work[itau], &work[iwrk], &i__1,
            &ierr);

    if (wantvs) {

        /*        Copy Householder vectors to VS */

        dlacpy_("L", n, n, &a[a_offset], lda, &vs[vs_offset], ldvs)
        ;

        /*        Generate orthogonal matrix in VS */
        /*        (Workspace: need 3*N-1, prefer 2*N+(N-1)*NB) */

        i__1 = *lwork - iwrk + 1;
        dorghr_(n, &ilo, &ihi, &vs[vs_offset], ldvs, &work[itau], &work[iwrk],
                &i__1, &ierr);
    }

    *sdim = 0;

    /*     Perform QR iteration, accumulating Schur vectors in VS if desired */
    /*     (Workspace: need N+1, prefer N+HSWORK (see comments) ) */

    iwrk = itau;
    i__1 = *lwork - iwrk + 1;
    dhseqr_("S", jobvs, n, &ilo, &ihi, &a[a_offset], lda, &wr[1], &wi[1], &vs[
                vs_offset], ldvs, &work[iwrk], &i__1, &ieval);
    if (ieval > 0) {
        *info = ieval;
    }

    /*     Sort eigenvalues if desired */

    if (wantst && *info == 0) {
        if (scalea) {
            dlascl_("G", &c__0, &c__0, &cscale, &anrm, n, &c__1, &wr[1], n, &
                    ierr);
            dlascl_("G", &c__0, &c__0, &cscale, &anrm, n, &c__1, &wi[1], n, &
                    ierr);
        }
        i__1 = *n;
        for (i__ = 1; i__ <= i__1; ++i__) {
            bwork[i__] = (*select)(&wr[i__], &wi[i__]);
            /* L10: */
        }

        /*        Reorder eigenvalues and transform Schur vectors */
        /*        (Workspace: none needed) */

        i__1 = *lwork - iwrk + 1;
        dtrsen_("N", jobvs, &bwork[1], n, &a[a_offset], lda, &vs[vs_offset],
                ldvs, &wr[1], &wi[1], sdim, &s, &sep, &work[iwrk], &i__1,
                idum, &c__1, &icond);
        if (icond > 0) {
            *info = *n + icond;
        }
    }

    if (wantvs) {

        /*        Undo balancing */
        /*        (Workspace: need N) */

        dgebak_("P", "R", n, &ilo, &ihi, &work[ibal], n, &vs[vs_offset], ldvs,
                &ierr);
    }

    if (scalea) {

        /*        Undo scaling for the Schur form of A */

        dlascl_("H", &c__0, &c__0, &cscale, &anrm, n, n, &a[a_offset], lda, &
                ierr);
        i__1 = *lda + 1;
        dcopy_(n, &a[a_offset], &i__1, &wr[1], &c__1);
        if (cscale == smlnum) {

            /*           If scaling back towards underflow, adjust WI if an */
            /*           offdiagonal element of a 2-by-2 block in the Schur form */
            /*           underflows. */

            if (ieval > 0) {
                i1 = ieval + 1;
                i2 = ihi - 1;
                i__1 = ilo - 1;
                /* Computing MAX */
                i__3 = ilo - 1;
                i__2 = max(i__3,1);
                dlascl_("G", &c__0, &c__0, &cscale, &anrm, &i__1, &c__1, &wi[
                            1], &i__2, &ierr);
            } else if (wantst) {
                i1 = 1;
                i2 = *n - 1;
            } else {
                i1 = ilo;
                i2 = ihi - 1;
            }
            inxt = i1 - 1;
            i__1 = i2;
            for (i__ = i1; i__ <= i__1; ++i__) {
                if (i__ < inxt) {
                    goto L20;
                }
                if (wi[i__] == 0.) {
                    inxt = i__ + 1;
                } else {
                    if (a[i__ + 1 + i__ * a_dim1] == 0.) {
                        wi[i__] = 0.;
                        wi[i__ + 1] = 0.;
                    } else if (a[i__ + 1 + i__ * a_dim1] != 0. && a[i__ + (
                                   i__ + 1) * a_dim1] == 0.) {
                        wi[i__] = 0.;
                        wi[i__ + 1] = 0.;
                        if (i__ > 1) {
                            i__2 = i__ - 1;
                            dswap_(&i__2, &a[i__ * a_dim1 + 1], &c__1, &a[(
                                        i__ + 1) * a_dim1 + 1], &c__1);
                        }
                        if (*n > i__ + 1) {
                            i__2 = *n - i__ - 1;
                            dswap_(&i__2, &a[i__ + (i__ + 2) * a_dim1], lda, &
                                   a[i__ + 1 + (i__ + 2) * a_dim1], lda);
                        }
                        if (wantvs) {
                            dswap_(n, &vs[i__ * vs_dim1 + 1], &c__1, &vs[(i__
                                    + 1) * vs_dim1 + 1], &c__1);
                        }
                        a[i__ + (i__ + 1) * a_dim1] = a[i__ + 1 + i__ *
                                                        a_dim1];
                        a[i__ + 1 + i__ * a_dim1] = 0.;
                    }
                    inxt = i__ + 2;
                }
L20:
                ;
            }
        }

        /*        Undo scaling for the imaginary part of the eigenvalues */

        i__1 = *n - ieval;
        /* Computing MAX */
        i__3 = *n - ieval;
        i__2 = max(i__3,1);
        dlascl_("G", &c__0, &c__0, &cscale, &anrm, &i__1, &c__1, &wi[ieval +
                1], &i__2, &ierr);
    }

    if (wantst && *info == 0) {

        /*        Check if reordering successful */

        lastsl = TRUE_;
        lst2sl = TRUE_;
        *sdim = 0;
        ip = 0;
        i__1 = *n;
        for (i__ = 1; i__ <= i__1; ++i__) {
            cursl = (*select)(&wr[i__], &wi[i__]);
            if (wi[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;
            /* L30: */
        }
    }

    work[1] = (doublereal) maxwrk;
    return 0;

    /*     End of DGEES */

} /* dgees_ */
/* Subroutine */ int dget38_(doublereal *rmax, integer *lmax, integer *ninfo, 
	integer *knt, integer *nin)
{
    /* System generated locals */
    integer i__1, i__2;
    doublereal d__1, d__2;

    /* Local variables */
    integer i__, j, m, n;
    doublereal q[400]	/* was [20][20] */, s, t[400]	/* was [20][20] */, v,
	     wi[20], wr[20], val[3], eps, sep, sin__, tol, tmp[400]	/* 
	    was [20][20] */;
    integer ndim, iscl, info, kmin, itmp, ipnt[20];
    doublereal vmax, qsav[400]	/* was [20][20] */, tsav[400]	/* was [20][
	    20] */, tnrm, qtmp[400]	/* was [20][20] */, work[1200], stmp, 
	    vmul, ttmp[400]	/* was [20][20] */, tsav1[400]	/* was [20][
	    20] */;
    extern /* Subroutine */ int dscal_(integer *, doublereal *, doublereal *, 
	    integer *), dhst01_(integer *, integer *, integer *, doublereal *, 
	     integer *, doublereal *, integer *, doublereal *, integer *, 
	    doublereal *, integer *, doublereal *);
    doublereal sepin;
    extern /* Subroutine */ int dcopy_(integer *, doublereal *, integer *, 
	    doublereal *, integer *);
    doublereal vimin, tolin, vrmin;
    integer iwork[400];
    doublereal witmp[20], wrtmp[20];
    extern /* Subroutine */ int dlabad_(doublereal *, doublereal *);
    extern doublereal dlamch_(char *), dlange_(char *, integer *, 
	    integer *, doublereal *, integer *, doublereal *);
    extern /* Subroutine */ int dgehrd_(integer *, integer *, integer *, 
	    doublereal *, integer *, doublereal *, doublereal *, integer *, 
	    integer *);
    integer iselec[20];
    extern /* Subroutine */ int dlacpy_(char *, integer *, integer *, 
	    doublereal *, integer *, doublereal *, integer *);
    logical select[20];
    doublereal bignum;
    extern /* Subroutine */ int dorghr_(integer *, integer *, integer *, 
	    doublereal *, integer *, doublereal *, doublereal *, integer *, 
	    integer *), dhseqr_(char *, char *, integer *, integer *, integer 
	    *, doublereal *, integer *, doublereal *, doublereal *, 
	    doublereal *, integer *, doublereal *, integer *, integer *), dtrsen_(char *, char *, logical *, integer *, 
	    doublereal *, integer *, doublereal *, integer *, doublereal *, 
	    doublereal *, integer *, doublereal *, doublereal *, doublereal *, 
	     integer *, integer *, integer *, integer *);
    doublereal septmp, smlnum, result[2];

    /* Fortran I/O blocks */
    static cilist io___5 = { 0, 0, 0, 0, 0 };
    static cilist io___8 = { 0, 0, 0, 0, 0 };
    static cilist io___11 = { 0, 0, 0, 0, 0 };
    static cilist io___14 = { 0, 0, 0, 0, 0 };



/*  -- LAPACK test routine (version 3.1) -- */
/*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. */
/*     November 2006 */

/*     .. Scalar Arguments .. */
/*     .. */
/*     .. Array Arguments .. */
/*     .. */

/*  Purpose */
/*  ======= */

/*  DGET38 tests DTRSEN, a routine for estimating condition numbers of a */
/*  cluster of eigenvalues and/or its associated right invariant subspace */

/*  The test matrices are read from a file with logical unit number NIN. */

/*  Arguments */
/*  ========== */

/*  RMAX    (output) DOUBLE PRECISION array, dimension (3) */
/*          Values of the largest test ratios. */
/*          RMAX(1) = largest residuals from DHST01 or comparing */
/*                    different calls to DTRSEN */
/*          RMAX(2) = largest error in reciprocal condition */
/*                    numbers taking their conditioning into account */
/*          RMAX(3) = largest error in reciprocal condition */
/*                    numbers not taking their conditioning into */
/*                    account (may be larger than RMAX(2)) */

/*  LMAX    (output) INTEGER array, dimension (3) */
/*          LMAX(i) is example number where largest test ratio */
/*          RMAX(i) is achieved. Also: */
/*          If DGEHRD returns INFO nonzero on example i, LMAX(1)=i */
/*          If DHSEQR returns INFO nonzero on example i, LMAX(2)=i */
/*          If DTRSEN returns INFO nonzero on example i, LMAX(3)=i */

/*  NINFO   (output) INTEGER array, dimension (3) */
/*          NINFO(1) = No. of times DGEHRD returned INFO nonzero */
/*          NINFO(2) = No. of times DHSEQR returned INFO nonzero */
/*          NINFO(3) = No. of times DTRSEN returned INFO nonzero */

/*  KNT     (output) INTEGER */
/*          Total number of examples tested. */

/*  NIN     (input) INTEGER */
/*          Input logical unit number. */

/*  ===================================================================== */

/*     .. Parameters .. */
/*     .. */
/*     .. Local Scalars .. */
/*     .. */
/*     .. Local Arrays .. */
/*     .. */
/*     .. External Functions .. */
/*     .. */
/*     .. External Subroutines .. */
/*     .. */
/*     .. Intrinsic Functions .. */
/*     .. */
/*     .. Executable Statements .. */

    /* Parameter adjustments */
    --ninfo;
    --lmax;
    --rmax;

    /* Function Body */
    eps = dlamch_("P");
    smlnum = dlamch_("S") / eps;
    bignum = 1. / smlnum;
    dlabad_(&smlnum, &bignum);

/*     EPSIN = 2**(-24) = precision to which input data computed */

    eps = max(eps,5.9605e-8);
    rmax[1] = 0.;
    rmax[2] = 0.;
    rmax[3] = 0.;
    lmax[1] = 0;
    lmax[2] = 0;
    lmax[3] = 0;
    *knt = 0;
    ninfo[1] = 0;
    ninfo[2] = 0;
    ninfo[3] = 0;

    val[0] = sqrt(smlnum);
    val[1] = 1.;
    val[2] = sqrt(sqrt(bignum));

/*     Read input data until N=0.  Assume input eigenvalues are sorted */
/*     lexicographically (increasing by real part, then decreasing by */
/*     imaginary part) */

L10:
    io___5.ciunit = *nin;
    s_rsle(&io___5);
    do_lio(&c__3, &c__1, (char *)&n, (ftnlen)sizeof(integer));
    do_lio(&c__3, &c__1, (char *)&ndim, (ftnlen)sizeof(integer));
    e_rsle();
    if (n == 0) {
	return 0;
    }
    io___8.ciunit = *nin;
    s_rsle(&io___8);
    i__1 = ndim;
    for (i__ = 1; i__ <= i__1; ++i__) {
	do_lio(&c__3, &c__1, (char *)&iselec[i__ - 1], (ftnlen)sizeof(integer)
		);
    }
    e_rsle();
    i__1 = n;
    for (i__ = 1; i__ <= i__1; ++i__) {
	io___11.ciunit = *nin;
	s_rsle(&io___11);
	i__2 = n;
	for (j = 1; j <= i__2; ++j) {
	    do_lio(&c__5, &c__1, (char *)&tmp[i__ + j * 20 - 21], (ftnlen)
		    sizeof(doublereal));
	}
	e_rsle();
/* L20: */
    }
    io___14.ciunit = *nin;
    s_rsle(&io___14);
    do_lio(&c__5, &c__1, (char *)&sin__, (ftnlen)sizeof(doublereal));
    do_lio(&c__5, &c__1, (char *)&sepin, (ftnlen)sizeof(doublereal));
    e_rsle();

    tnrm = dlange_("M", &n, &n, tmp, &c__20, work);
    for (iscl = 1; iscl <= 3; ++iscl) {

/*        Scale input matrix */

	++(*knt);
	dlacpy_("F", &n, &n, tmp, &c__20, t, &c__20);
	vmul = val[iscl - 1];
	i__1 = n;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    dscal_(&n, &vmul, &t[i__ * 20 - 20], &c__1);
/* L30: */
	}
	if (tnrm == 0.) {
	    vmul = 1.;
	}
	dlacpy_("F", &n, &n, t, &c__20, tsav, &c__20);

/*        Compute Schur form */

	i__1 = 1200 - n;
	dgehrd_(&n, &c__1, &n, t, &c__20, work, &work[n], &i__1, &info);
	if (info != 0) {
	    lmax[1] = *knt;
	    ++ninfo[1];
	    goto L160;
	}

/*        Generate orthogonal matrix */

	dlacpy_("L", &n, &n, t, &c__20, q, &c__20);
	i__1 = 1200 - n;
	dorghr_(&n, &c__1, &n, q, &c__20, work, &work[n], &i__1, &info);

/*        Compute Schur form */

	dhseqr_("S", "V", &n, &c__1, &n, t, &c__20, wr, wi, q, &c__20, work, &
		c__1200, &info);
	if (info != 0) {
	    lmax[2] = *knt;
	    ++ninfo[2];
	    goto L160;
	}

/*        Sort, select eigenvalues */

	i__1 = n;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    ipnt[i__ - 1] = i__;
	    select[i__ - 1] = FALSE_;
/* L40: */
	}
	dcopy_(&n, wr, &c__1, wrtmp, &c__1);
	dcopy_(&n, wi, &c__1, witmp, &c__1);
	i__1 = n - 1;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    kmin = i__;
	    vrmin = wrtmp[i__ - 1];
	    vimin = witmp[i__ - 1];
	    i__2 = n;
	    for (j = i__ + 1; j <= i__2; ++j) {
		if (wrtmp[j - 1] < vrmin) {
		    kmin = j;
		    vrmin = wrtmp[j - 1];
		    vimin = witmp[j - 1];
		}
/* L50: */
	    }
	    wrtmp[kmin - 1] = wrtmp[i__ - 1];
	    witmp[kmin - 1] = witmp[i__ - 1];
	    wrtmp[i__ - 1] = vrmin;
	    witmp[i__ - 1] = vimin;
	    itmp = ipnt[i__ - 1];
	    ipnt[i__ - 1] = ipnt[kmin - 1];
	    ipnt[kmin - 1] = itmp;
/* L60: */
	}
	i__1 = ndim;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    select[ipnt[iselec[i__ - 1] - 1] - 1] = TRUE_;
/* L70: */
	}

/*        Compute condition numbers */

	dlacpy_("F", &n, &n, q, &c__20, qsav, &c__20);
	dlacpy_("F", &n, &n, t, &c__20, tsav1, &c__20);
	dtrsen_("B", "V", select, &n, t, &c__20, q, &c__20, wrtmp, witmp, &m, 
		&s, &sep, work, &c__1200, iwork, &c__400, &info);
	if (info != 0) {
	    lmax[3] = *knt;
	    ++ninfo[3];
	    goto L160;
	}
	septmp = sep / vmul;
	stmp = s;

/*        Compute residuals */

	dhst01_(&n, &c__1, &n, tsav, &c__20, t, &c__20, q, &c__20, work, &
		c__1200, result);
	vmax = max(result[0],result[1]);
	if (vmax > rmax[1]) {
	    rmax[1] = vmax;
	    if (ninfo[1] == 0) {
		lmax[1] = *knt;
	    }
	}

/*        Compare condition number for eigenvalue cluster */
/*        taking its condition number into account */

/* Computing MAX */
	d__1 = (doublereal) n * 2. * eps * tnrm;
	v = max(d__1,smlnum);
	if (tnrm == 0.) {
	    v = 1.;
	}
	if (v > septmp) {
	    tol = 1.;
	} else {
	    tol = v / septmp;
	}
	if (v > sepin) {
	    tolin = 1.;
	} else {
	    tolin = v / sepin;
	}
/* Computing MAX */
	d__1 = tol, d__2 = smlnum / eps;
	tol = max(d__1,d__2);
/* Computing MAX */
	d__1 = tolin, d__2 = smlnum / eps;
	tolin = max(d__1,d__2);
	if (eps * (sin__ - tolin) > stmp + tol) {
	    vmax = 1. / eps;
	} else if (sin__ - tolin > stmp + tol) {
	    vmax = (sin__ - tolin) / (stmp + tol);
	} else if (sin__ + tolin < eps * (stmp - tol)) {
	    vmax = 1. / eps;
	} else if (sin__ + tolin < stmp - tol) {
	    vmax = (stmp - tol) / (sin__ + tolin);
	} else {
	    vmax = 1.;
	}
	if (vmax > rmax[2]) {
	    rmax[2] = vmax;
	    if (ninfo[2] == 0) {
		lmax[2] = *knt;
	    }
	}

/*        Compare condition numbers for invariant subspace */
/*        taking its condition number into account */

	if (v > septmp * stmp) {
	    tol = septmp;
	} else {
	    tol = v / stmp;
	}
	if (v > sepin * sin__) {
	    tolin = sepin;
	} else {
	    tolin = v / sin__;
	}
/* Computing MAX */
	d__1 = tol, d__2 = smlnum / eps;
	tol = max(d__1,d__2);
/* Computing MAX */
	d__1 = tolin, d__2 = smlnum / eps;
	tolin = max(d__1,d__2);
	if (eps * (sepin - tolin) > septmp + tol) {
	    vmax = 1. / eps;
	} else if (sepin - tolin > septmp + tol) {
	    vmax = (sepin - tolin) / (septmp + tol);
	} else if (sepin + tolin < eps * (septmp - tol)) {
	    vmax = 1. / eps;
	} else if (sepin + tolin < septmp - tol) {
	    vmax = (septmp - tol) / (sepin + tolin);
	} else {
	    vmax = 1.;
	}
	if (vmax > rmax[2]) {
	    rmax[2] = vmax;
	    if (ninfo[2] == 0) {
		lmax[2] = *knt;
	    }
	}

/*        Compare condition number for eigenvalue cluster */
/*        without taking its condition number into account */

	if (sin__ <= (doublereal) (n << 1) * eps && stmp <= (doublereal) (n <<
		 1) * eps) {
	    vmax = 1.;
	} else if (eps * sin__ > stmp) {
	    vmax = 1. / eps;
	} else if (sin__ > stmp) {
	    vmax = sin__ / stmp;
	} else if (sin__ < eps * stmp) {
	    vmax = 1. / eps;
	} else if (sin__ < stmp) {
	    vmax = stmp / sin__;
	} else {
	    vmax = 1.;
	}
	if (vmax > rmax[3]) {
	    rmax[3] = vmax;
	    if (ninfo[3] == 0) {
		lmax[3] = *knt;
	    }
	}

/*        Compare condition numbers for invariant subspace */
/*        without taking its condition number into account */

	if (sepin <= v && septmp <= v) {
	    vmax = 1.;
	} else if (eps * sepin > septmp) {
	    vmax = 1. / eps;
	} else if (sepin > septmp) {
	    vmax = sepin / septmp;
	} else if (sepin < eps * septmp) {
	    vmax = 1. / eps;
	} else if (sepin < septmp) {
	    vmax = septmp / sepin;
	} else {
	    vmax = 1.;
	}
	if (vmax > rmax[3]) {
	    rmax[3] = vmax;
	    if (ninfo[3] == 0) {
		lmax[3] = *knt;
	    }
	}

/*        Compute eigenvalue condition number only and compare */
/*        Update Q */

	vmax = 0.;
	dlacpy_("F", &n, &n, tsav1, &c__20, ttmp, &c__20);
	dlacpy_("F", &n, &n, qsav, &c__20, qtmp, &c__20);
	septmp = -1.;
	stmp = -1.;
	dtrsen_("E", "V", select, &n, ttmp, &c__20, qtmp, &c__20, wrtmp, 
		witmp, &m, &stmp, &septmp, work, &c__1200, iwork, &c__400, &
		info);
	if (info != 0) {
	    lmax[3] = *knt;
	    ++ninfo[3];
	    goto L160;
	}
	if (s != stmp) {
	    vmax = 1. / eps;
	}
	if (-1. != septmp) {
	    vmax = 1. / eps;
	}
	i__1 = n;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    i__2 = n;
	    for (j = 1; j <= i__2; ++j) {
		if (ttmp[i__ + j * 20 - 21] != t[i__ + j * 20 - 21]) {
		    vmax = 1. / eps;
		}
		if (qtmp[i__ + j * 20 - 21] != q[i__ + j * 20 - 21]) {
		    vmax = 1. / eps;
		}
/* L80: */
	    }
/* L90: */
	}

/*        Compute invariant subspace condition number only and compare */
/*        Update Q */

	dlacpy_("F", &n, &n, tsav1, &c__20, ttmp, &c__20);
	dlacpy_("F", &n, &n, qsav, &c__20, qtmp, &c__20);
	septmp = -1.;
	stmp = -1.;
	dtrsen_("V", "V", select, &n, ttmp, &c__20, qtmp, &c__20, wrtmp, 
		witmp, &m, &stmp, &septmp, work, &c__1200, iwork, &c__400, &
		info);
	if (info != 0) {
	    lmax[3] = *knt;
	    ++ninfo[3];
	    goto L160;
	}
	if (-1. != stmp) {
	    vmax = 1. / eps;
	}
	if (sep != septmp) {
	    vmax = 1. / eps;
	}
	i__1 = n;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    i__2 = n;
	    for (j = 1; j <= i__2; ++j) {
		if (ttmp[i__ + j * 20 - 21] != t[i__ + j * 20 - 21]) {
		    vmax = 1. / eps;
		}
		if (qtmp[i__ + j * 20 - 21] != q[i__ + j * 20 - 21]) {
		    vmax = 1. / eps;
		}
/* L100: */
	    }
/* L110: */
	}

/*        Compute eigenvalue condition number only and compare */
/*        Do not update Q */

	dlacpy_("F", &n, &n, tsav1, &c__20, ttmp, &c__20);
	dlacpy_("F", &n, &n, qsav, &c__20, qtmp, &c__20);
	septmp = -1.;
	stmp = -1.;
	dtrsen_("E", "N", select, &n, ttmp, &c__20, qtmp, &c__20, wrtmp, 
		witmp, &m, &stmp, &septmp, work, &c__1200, iwork, &c__400, &
		info);
	if (info != 0) {
	    lmax[3] = *knt;
	    ++ninfo[3];
	    goto L160;
	}
	if (s != stmp) {
	    vmax = 1. / eps;
	}
	if (-1. != septmp) {
	    vmax = 1. / eps;
	}
	i__1 = n;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    i__2 = n;
	    for (j = 1; j <= i__2; ++j) {
		if (ttmp[i__ + j * 20 - 21] != t[i__ + j * 20 - 21]) {
		    vmax = 1. / eps;
		}
		if (qtmp[i__ + j * 20 - 21] != qsav[i__ + j * 20 - 21]) {
		    vmax = 1. / eps;
		}
/* L120: */
	    }
/* L130: */
	}

/*        Compute invariant subspace condition number only and compare */
/*        Do not update Q */

	dlacpy_("F", &n, &n, tsav1, &c__20, ttmp, &c__20);
	dlacpy_("F", &n, &n, qsav, &c__20, qtmp, &c__20);
	septmp = -1.;
	stmp = -1.;
	dtrsen_("V", "N", select, &n, ttmp, &c__20, qtmp, &c__20, wrtmp, 
		witmp, &m, &stmp, &septmp, work, &c__1200, iwork, &c__400, &
		info);
	if (info != 0) {
	    lmax[3] = *knt;
	    ++ninfo[3];
	    goto L160;
	}
	if (-1. != stmp) {
	    vmax = 1. / eps;
	}
	if (sep != septmp) {
	    vmax = 1. / eps;
	}
	i__1 = n;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    i__2 = n;
	    for (j = 1; j <= i__2; ++j) {
		if (ttmp[i__ + j * 20 - 21] != t[i__ + j * 20 - 21]) {
		    vmax = 1. / eps;
		}
		if (qtmp[i__ + j * 20 - 21] != qsav[i__ + j * 20 - 21]) {
		    vmax = 1. / eps;
		}
/* L140: */
	    }
/* L150: */
	}
	if (vmax > rmax[1]) {
	    rmax[1] = vmax;
	    if (ninfo[1] == 0) {
		lmax[1] = *knt;
	    }
	}
L160:
	;
    }
    goto L10;

/*     End of DGET38 */

} /* dget38_ */
/* Subroutine */ int dgeesx_(char *jobvs, char *sort, L_fp select, char *
	sense, integer *n, doublereal *a, integer *lda, integer *sdim, 
	doublereal *wr, doublereal *wi, doublereal *vs, integer *ldvs, 
	doublereal *rconde, doublereal *rcondv, doublereal *work, integer *
	lwork, integer *iwork, integer *liwork, logical *bwork, integer *info)
{
    /* System generated locals */
    integer a_dim1, a_offset, vs_dim1, vs_offset, i__1, i__2, i__3;

    /* Local variables */
    integer i__, i1, i2, ip, ihi, ilo;
    doublereal dum[1], eps;
    integer ibal;
    doublereal anrm;
    integer ierr, itau, iwrk, lwrk, inxt, icond, ieval;
    logical cursl;
    integer liwrk;
    logical lst2sl, scalea;
    doublereal cscale;
    doublereal bignum;
    logical wantsb;
    logical wantse, lastsl;
    integer minwrk, maxwrk;
    logical wantsn;
    doublereal smlnum;
    integer hswork;
    logical wantst, lquery, wantsv, wantvs;

/*  -- LAPACK driver routine (version 3.2) -- */
/*     November 2006 */

/*  Purpose */
/*  ======= */

/*  DGEESX computes for an N-by-N real nonsymmetric matrix A, the */
/*  eigenvalues, the real Schur form T, and, optionally, the matrix of */
/*  Schur vectors Z.  This gives the Schur factorization A = Z*T*(Z**T). */

/*  Optionally, it also orders the eigenvalues on the diagonal of the */
/*  real 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 real matrix is in real Schur form if it is upper quasi-triangular */
/*  with 1-by-1 and 2-by-2 blocks. 2-by-2 blocks will be standardized in */
/*  the form */
/*            [  a  b  ] */
/*            [  c  a  ] */

/*  where b*c < 0. The eigenvalues of such a block are a +- sqrt(bc). */

/*  Arguments */
/*  ========= */

/*  JOBVS   (input) CHARACTER*1 */
/*          = 'N': Schur vectors are not computed; */
/*          = 'V': Schur vectors are computed. */

/*  SORT    (input) CHARACTER*1 */
/*          Specifies whether or not to order the eigenvalues on the */
/*          diagonal of the Schur form. */
/*          = 'N': Eigenvalues are not ordered; */
/*          = 'S': Eigenvalues are ordered (see SELECT). */

/*  SELECT  (external procedure) LOGICAL FUNCTION of two DOUBLE PRECISION arguments */
/*          SELECT must be declared EXTERNAL in the calling subroutine. */
/*          If SORT = 'S', SELECT is used to select eigenvalues to sort */
/*          to the top left of the Schur form. */
/*          If SORT = 'N', SELECT is not referenced. */
/*          An eigenvalue WR(j)+sqrt(-1)*WI(j) is selected if */
/*          SELECT(WR(j),WI(j)) is true; i.e., if either one of a */
/*          complex conjugate pair of eigenvalues is selected, then both */
/*          are.  Note that a selected complex eigenvalue may no longer */
/*          satisfy SELECT(WR(j),WI(j)) = .TRUE. after ordering, since */
/*          ordering may change the value of complex eigenvalues */
/*          (especially if the eigenvalue is ill-conditioned); in this */
/*          case INFO may be set to N+3 (see INFO below). */

/*  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 right invariant subspace only; */
/*          = 'B': Computed for both. */
/*          If SENSE = 'E', 'V' or 'B', SORT must equal 'S'. */

/*  N       (input) INTEGER */
/*          The order of the matrix A. N >= 0. */

/*  A       (input/output) DOUBLE PRECISION array, dimension (LDA, N) */
/*          On entry, the N-by-N matrix A. */
/*          On exit, A is overwritten by its real Schur form T. */

/*  LDA     (input) INTEGER */
/*          The leading dimension of the array A.  LDA >= max(1,N). */

/*  SDIM    (output) INTEGER */
/*          If SORT = 'N', SDIM = 0. */
/*          If SORT = 'S', SDIM = number of eigenvalues (after sorting) */
/*                         for which SELECT is true. (Complex conjugate */
/*                         pairs for which SELECT is true for either */
/*                         eigenvalue count as 2.) */

/*  WR      (output) DOUBLE PRECISION array, dimension (N) */
/*  WI      (output) DOUBLE PRECISION array, dimension (N) */
/*          WR and WI contain the real and imaginary parts, respectively, */
/*          of the computed eigenvalues, in the same order that they */
/*          appear on the diagonal of the output Schur form T.  Complex */
/*          conjugate pairs of eigenvalues appear consecutively with the */
/*          eigenvalue having the positive imaginary part first. */

/*  VS      (output) DOUBLE PRECISION array, dimension (LDVS,N) */
/*          If JOBVS = 'V', VS contains the orthogonal matrix Z of Schur */
/*          vectors. */
/*          If JOBVS = 'N', VS is not referenced. */

/*  LDVS    (input) INTEGER */
/*          The leading dimension of the array VS.  LDVS >= 1, and if */
/*          JOBVS = 'V', LDVS >= N. */

/*  RCONDE  (output) DOUBLE PRECISION */
/*          If SENSE = 'E' or 'B', RCONDE contains the reciprocal */
/*          condition number for the average of the selected eigenvalues. */
/*          Not referenced if SENSE = 'N' or 'V'. */

/*  RCONDV  (output) DOUBLE PRECISION */
/*          If SENSE = 'V' or 'B', RCONDV contains the reciprocal */
/*          condition number for the selected right invariant subspace. */
/*          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.  LWORK >= max(1,3*N). */
/*          Also, if SENSE = 'E' or 'V' or 'B', */
/*          LWORK >= N+2*SDIM*(N-SDIM), where SDIM is the number of */
/*          selected eigenvalues computed by this routine.  Note that */
/*          N+2*SDIM*(N-SDIM) <= N+N*N/2. Note also that an error is only */
/*          returned if LWORK < max(1,3*N), but if SENSE = 'E' or 'V' or */
/*          'B' this may not be large enough. */
/*          For good performance, LWORK must generally be larger. */

/*          If LWORK = -1, then a workspace query is assumed; the routine */
/*          only calculates upper bounds on the optimal sizes of the */
/*          arrays WORK and IWORK, returns these values as the first */
/*          entries of the WORK and IWORK arrays, and no error messages */
/*          related to LWORK or LIWORK are issued by XERBLA. */

/*  IWORK   (workspace/output) INTEGER array, dimension (MAX(1,LIWORK)) */
/*          On exit, if INFO = 0, IWORK(1) returns the optimal LIWORK. */

/*  LIWORK  (input) INTEGER */
/*          The dimension of the array IWORK. */
/*          LIWORK >= 1; if SENSE = 'V' or 'B', LIWORK >= SDIM*(N-SDIM). */
/*          Note that SDIM*(N-SDIM) <= N*N/4. Note also that an error is */
/*          only returned if LIWORK < 1, but if SENSE = 'V' or 'B' this */
/*          may not be large enough. */

/*          If LIWORK = -1, then a workspace query is assumed; the */
/*          routine only calculates upper bounds on the optimal sizes of */
/*          the arrays WORK and IWORK, returns these values as the first */
/*          entries of the WORK and IWORK arrays, and no error messages */
/*          related to LWORK or LIWORK are 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. */
/*          > 0: if INFO = i, and i is */
/*             <= N: the QR algorithm failed to compute all the */
/*                   eigenvalues; elements 1:ILO-1 and i+1:N of WR and WI */
/*                   contain those eigenvalues which have converged; if */
/*                   JOBVS = 'V', VS contains the transformation which */
/*                   reduces A to its partially converged Schur form. */
/*             = N+1: the eigenvalues could not be reordered because some */
/*                   eigenvalues were too close to separate (the problem */
/*                   is very ill-conditioned); */
/*             = N+2: after reordering, roundoff changed values of some */
/*                   complex eigenvalues so that leading eigenvalues in */
/*                   the Schur form no longer satisfy SELECT=.TRUE.  This */
/*                   could also be caused by underflow due to scaling. */

/*  ===================================================================== */

/*     Test the input arguments */

    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --wr;
    --wi;
    vs_dim1 = *ldvs;
    vs_offset = 1 + vs_dim1;
    vs -= vs_offset;
    --work;
    --iwork;
    --bwork;

    /* Function Body */
    *info = 0;
    wantvs = lsame_(jobvs, "V");
    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 (! wantvs && ! lsame_(jobvs, "N")) {
	*info = -1;
    } else if (! wantst && ! lsame_(sort, "N")) {
	*info = -2;
    } else if (! (wantsn || wantse || wantsv || wantsb) || ! wantst && ! 
	    wantsn) {
	*info = -4;
    } else if (*n < 0) {
	*info = -5;
    } else if (*lda < max(1,*n)) {
	*info = -7;
    } else if (*ldvs < 1 || wantvs && *ldvs < *n) {
	*info = -12;
    }

/*     Compute workspace */
/*      (Note: Comments in the code beginning "RWorkspace:" describe the */
/*       minimal amount of real workspace needed at that point in the */
/*       code, as well as the preferred amount for good performance. */
/*       IWorkspace refers to integer workspace. */
/*       NB refers to the optimal block size for the immediately */
/*       following subroutine, as returned by ILAENV. */
/*       HSWORK refers to the workspace preferred by DHSEQR, as */
/*       calculated below. HSWORK is computed assuming ILO=1 and IHI=N, */
/*       the worst case. */
/*       If SENSE = 'E', 'V' or 'B', then the amount of workspace needed */
/*       depends on SDIM, which is computed by the routine DTRSEN later */
/*       in the code.) */

    if (*info == 0) {
	liwrk = 1;
	if (*n == 0) {
	    minwrk = 1;
	    lwrk = 1;
	} else {
	    maxwrk = (*n << 1) + *n * ilaenv_(&c__1, "DGEHRD", " ", n, &c__1, 
		    n, &c__0);
	    minwrk = *n * 3;

	    dhseqr_("S", jobvs, n, &c__1, n, &a[a_offset], lda, &wr[1], &wi[1]
, &vs[vs_offset], ldvs, &work[1], &c_n1, &ieval);
	    hswork = (integer) work[1];

	    if (! wantvs) {
/* Computing MAX */
		i__1 = maxwrk, i__2 = *n + hswork;
		maxwrk = max(i__1,i__2);
	    } else {
/* Computing MAX */
		i__1 = maxwrk, i__2 = (*n << 1) + (*n - 1) * ilaenv_(&c__1, 
			"DORGHR", " ", n, &c__1, n, &c_n1);
		maxwrk = max(i__1,i__2);
/* Computing MAX */
		i__1 = maxwrk, i__2 = *n + hswork;
		maxwrk = max(i__1,i__2);
	    }
	    lwrk = maxwrk;
	    if (! wantsn) {
/* Computing MAX */
		i__1 = lwrk, i__2 = *n + *n * *n / 2;
		lwrk = max(i__1,i__2);
	    }
	    if (wantsv || wantsb) {
		liwrk = *n * *n / 4;
	    }
	}
	iwork[1] = liwrk;
	work[1] = (doublereal) lwrk;

	if (*lwork < minwrk && ! lquery) {
	    *info = -16;
	} else if (*liwork < 1 && ! lquery) {
	    *info = -18;
	}
    }

    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("DGEESX", &i__1);
	return 0;
    }

/*     Quick return if possible */

    if (*n == 0) {
	*sdim = 0;
	return 0;
    }

/*     Get machine constants */

    eps = dlamch_("P");
    smlnum = dlamch_("S");
    bignum = 1. / smlnum;
    dlabad_(&smlnum, &bignum);
    smlnum = sqrt(smlnum) / eps;
    bignum = 1. / smlnum;

/*     Scale A if max element outside range [SMLNUM,BIGNUM] */

    anrm = dlange_("M", n, n, &a[a_offset], lda, dum);
    scalea = FALSE_;
    if (anrm > 0. && anrm < smlnum) {
	scalea = TRUE_;
	cscale = smlnum;
    } else if (anrm > bignum) {
	scalea = TRUE_;
	cscale = bignum;
    }
    if (scalea) {
	dlascl_("G", &c__0, &c__0, &anrm, &cscale, n, n, &a[a_offset], lda, &
		ierr);
    }

/*     Permute the matrix to make it more nearly triangular */
/*     (RWorkspace: need N) */

    ibal = 1;
    dgebal_("P", n, &a[a_offset], lda, &ilo, &ihi, &work[ibal], &ierr);

/*     Reduce to upper Hessenberg form */
/*     (RWorkspace: need 3*N, prefer 2*N+N*NB) */

    itau = *n + ibal;
    iwrk = *n + itau;
    i__1 = *lwork - iwrk + 1;
    dgehrd_(n, &ilo, &ihi, &a[a_offset], lda, &work[itau], &work[iwrk], &i__1, 
	     &ierr);

    if (wantvs) {

/*        Copy Householder vectors to VS */

	dlacpy_("L", n, n, &a[a_offset], lda, &vs[vs_offset], ldvs)
		;

/*        Generate orthogonal matrix in VS */
/*        (RWorkspace: need 3*N-1, prefer 2*N+(N-1)*NB) */

	i__1 = *lwork - iwrk + 1;
	dorghr_(n, &ilo, &ihi, &vs[vs_offset], ldvs, &work[itau], &work[iwrk], 
		 &i__1, &ierr);
    }

    *sdim = 0;

/*     Perform QR iteration, accumulating Schur vectors in VS if desired */
/*     (RWorkspace: need N+1, prefer N+HSWORK (see comments) ) */

    iwrk = itau;
    i__1 = *lwork - iwrk + 1;
    dhseqr_("S", jobvs, n, &ilo, &ihi, &a[a_offset], lda, &wr[1], &wi[1], &vs[
	    vs_offset], ldvs, &work[iwrk], &i__1, &ieval);
    if (ieval > 0) {
	*info = ieval;
    }

/*     Sort eigenvalues if desired */

    if (wantst && *info == 0) {
	if (scalea) {
	    dlascl_("G", &c__0, &c__0, &cscale, &anrm, n, &c__1, &wr[1], n, &
		    ierr);
	    dlascl_("G", &c__0, &c__0, &cscale, &anrm, n, &c__1, &wi[1], n, &
		    ierr);
	}
	i__1 = *n;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    bwork[i__] = (*select)(&wr[i__], &wi[i__]);
	}

/*        Reorder eigenvalues, transform Schur vectors, and compute */
/*        reciprocal condition numbers */
/*        (RWorkspace: if SENSE is not 'N', need N+2*SDIM*(N-SDIM) */
/*                     otherwise, need N ) */
/*        (IWorkspace: if SENSE is 'V' or 'B', need SDIM*(N-SDIM) */
/*                     otherwise, need 0 ) */

	i__1 = *lwork - iwrk + 1;
	dtrsen_(sense, jobvs, &bwork[1], n, &a[a_offset], lda, &vs[vs_offset], 
		 ldvs, &wr[1], &wi[1], sdim, rconde, rcondv, &work[iwrk], &
		i__1, &iwork[1], liwork, &icond);
	if (! wantsn) {
/* Computing MAX */
	    i__1 = maxwrk, i__2 = *n + (*sdim << 1) * (*n - *sdim);
	    maxwrk = max(i__1,i__2);
	}
	if (icond == -15) {

/*           Not enough real workspace */

	    *info = -16;
	} else if (icond == -17) {

/*           Not enough integer workspace */

	    *info = -18;
	} else if (icond > 0) {

/*           DTRSEN failed to reorder or to restore standard Schur form */

	    *info = icond + *n;
	}
    }

    if (wantvs) {

/*        Undo balancing */
/*        (RWorkspace: need N) */

	dgebak_("P", "R", n, &ilo, &ihi, &work[ibal], n, &vs[vs_offset], ldvs, 
		 &ierr);
    }

    if (scalea) {

/*        Undo scaling for the Schur form of A */

	dlascl_("H", &c__0, &c__0, &cscale, &anrm, n, n, &a[a_offset], lda, &
		ierr);
	i__1 = *lda + 1;
	dcopy_(n, &a[a_offset], &i__1, &wr[1], &c__1);
	if ((wantsv || wantsb) && *info == 0) {
	    dum[0] = *rcondv;
	    dlascl_("G", &c__0, &c__0, &cscale, &anrm, &c__1, &c__1, dum, &
		    c__1, &ierr);
	    *rcondv = dum[0];
	}
	if (cscale == smlnum) {

/*           If scaling back towards underflow, adjust WI if an */
/*           offdiagonal element of a 2-by-2 block in the Schur form */
/*           underflows. */

	    if (ieval > 0) {
		i1 = ieval + 1;
		i2 = ihi - 1;
		i__1 = ilo - 1;
		dlascl_("G", &c__0, &c__0, &cscale, &anrm, &i__1, &c__1, &wi[
			1], n, &ierr);
	    } else if (wantst) {
		i1 = 1;
		i2 = *n - 1;
	    } else {
		i1 = ilo;
		i2 = ihi - 1;
	    }
	    inxt = i1 - 1;
	    i__1 = i2;
	    for (i__ = i1; i__ <= i__1; ++i__) {
		if (i__ < inxt) {
		    goto L20;
		}
		if (wi[i__] == 0.) {
		    inxt = i__ + 1;
		} else {
		    if (a[i__ + 1 + i__ * a_dim1] == 0.) {
			wi[i__] = 0.;
			wi[i__ + 1] = 0.;
		    } else if (a[i__ + 1 + i__ * a_dim1] != 0. && a[i__ + (
			    i__ + 1) * a_dim1] == 0.) {
			wi[i__] = 0.;
			wi[i__ + 1] = 0.;
			if (i__ > 1) {
			    i__2 = i__ - 1;
			    dswap_(&i__2, &a[i__ * a_dim1 + 1], &c__1, &a[(
				    i__ + 1) * a_dim1 + 1], &c__1);
			}
			if (*n > i__ + 1) {
			    i__2 = *n - i__ - 1;
			    dswap_(&i__2, &a[i__ + (i__ + 2) * a_dim1], lda, &
				    a[i__ + 1 + (i__ + 2) * a_dim1], lda);
			}
			dswap_(n, &vs[i__ * vs_dim1 + 1], &c__1, &vs[(i__ + 1)
				 * vs_dim1 + 1], &c__1);
			a[i__ + (i__ + 1) * a_dim1] = a[i__ + 1 + i__ * 
				a_dim1];
			a[i__ + 1 + i__ * a_dim1] = 0.;
		    }
		    inxt = i__ + 2;
		}
L20:
		;
	    }
	}
	i__1 = *n - ieval;
/* Computing MAX */
	i__3 = *n - ieval;
	i__2 = max(i__3,1);
	dlascl_("G", &c__0, &c__0, &cscale, &anrm, &i__1, &c__1, &wi[ieval + 
		1], &i__2, &ierr);
    }

    if (wantst && *info == 0) {

/*        Check if reordering successful */

	lastsl = TRUE_;
	lst2sl = TRUE_;
	*sdim = 0;
	ip = 0;
	i__1 = *n;
	for (i__ = 1; i__ <= i__1; ++i__) {
	    cursl = (*select)(&wr[i__], &wi[i__]);
	    if (wi[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;
	}
    }

    work[1] = (doublereal) maxwrk;
    if (wantsv || wantsb) {
/* Computing MAX */
	i__1 = 1, i__2 = *sdim * (*n - *sdim);
	iwork[1] = max(i__1,i__2);
    } else {
	iwork[1] = 1;
    }

    return 0;

/*     End of DGEESX */

} /* dgeesx_ */
Exemple #4
0
/* Subroutine */
int dgees_(char *jobvs, char *sort, L_fp select, integer *n, doublereal *a, integer *lda, integer *sdim, doublereal *wr, doublereal *wi, doublereal *vs, integer *ldvs, doublereal *work, integer *lwork, logical *bwork, integer *info)
{
    /* System generated locals */
    integer a_dim1, a_offset, vs_dim1, vs_offset, i__1, i__2, i__3;
    /* Builtin functions */
    double sqrt(doublereal);
    /* Local variables */
    integer i__;
    doublereal s;
    integer i1, i2, ip, ihi, ilo;
    doublereal dum[1], eps, sep;
    integer ibal;
    doublereal anrm;
    integer idum[1], ierr, itau, iwrk, inxt, icond, ieval;
    extern logical lsame_(char *, char *);
    extern /* Subroutine */
    int dcopy_(integer *, doublereal *, integer *, doublereal *, integer *), dswap_(integer *, doublereal *, integer *, doublereal *, integer *);
    logical cursl;
    extern /* Subroutine */
    int dlabad_(doublereal *, doublereal *), dgebak_( char *, char *, integer *, integer *, integer *, doublereal *, integer *, doublereal *, integer *, integer *), dgebal_(char *, integer *, doublereal *, integer *, integer *, integer *, doublereal *, integer *);
    logical lst2sl, scalea;
    extern doublereal dlamch_(char *);
    doublereal cscale;
    extern doublereal dlange_(char *, integer *, integer *, doublereal *, integer *, doublereal *);
    extern /* Subroutine */
    int dgehrd_(integer *, integer *, integer *, doublereal *, integer *, doublereal *, doublereal *, integer *, integer *), dlascl_(char *, integer *, integer *, doublereal *, doublereal *, integer *, integer *, doublereal *, integer *, integer *), dlacpy_(char *, integer *, integer *, doublereal *, integer *, doublereal *, integer *), xerbla_(char *, integer *);
    extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *);
    doublereal bignum;
    extern /* Subroutine */
    int dorghr_(integer *, integer *, integer *, doublereal *, integer *, doublereal *, doublereal *, integer *, integer *), dhseqr_(char *, char *, integer *, integer *, integer *, doublereal *, integer *, doublereal *, doublereal *, doublereal *, integer *, doublereal *, integer *, integer *), dtrsen_(char *, char *, logical *, integer *, doublereal *, integer *, doublereal *, integer *, doublereal *, doublereal *, integer *, doublereal *, doublereal *, doublereal *, integer *, integer *, integer *, integer *);
    logical lastsl;
    integer minwrk, maxwrk;
    doublereal smlnum;
    integer hswork;
    logical wantst, lquery, wantvs;
    /* -- LAPACK driver routine (version 3.4.0) -- */
    /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
    /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
    /* November 2011 */
    /* .. Scalar Arguments .. */
    /* .. */
    /* .. Array Arguments .. */
    /* .. */
    /* .. Function Arguments .. */
    /* .. */
    /* ===================================================================== */
    /* .. Parameters .. */
    /* .. */
    /* .. Local Scalars .. */
    /* .. */
    /* .. Local Arrays .. */
    /* .. */
    /* .. External Subroutines .. */
    /* .. */
    /* .. External Functions .. */
    /* .. */
    /* .. Intrinsic Functions .. */
    /* .. */
    /* .. Executable Statements .. */
    /* Test the input arguments */
    /* Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1;
    a -= a_offset;
    --wr;
    --wi;
    vs_dim1 = *ldvs;
    vs_offset = 1 + vs_dim1;
    vs -= vs_offset;
    --work;
    --bwork;
    /* Function Body */
    *info = 0;
    lquery = *lwork == -1;
    wantvs = lsame_(jobvs, "V");
    wantst = lsame_(sort, "S");
    if (! wantvs && ! lsame_(jobvs, "N"))
    {
        *info = -1;
    }
    else if (! wantst && ! lsame_(sort, "N"))
    {
        *info = -2;
    }
    else if (*n < 0)
    {
        *info = -4;
    }
    else if (*lda < max(1,*n))
    {
        *info = -6;
    }
    else if (*ldvs < 1 || wantvs && *ldvs < *n)
    {
        *info = -11;
    }
    /* 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. */
    /* HSWORK refers to the workspace preferred by DHSEQR, as */
    /* calculated below. HSWORK is computed assuming ILO=1 and IHI=N, */
    /* the worst case.) */
    if (*info == 0)
    {
        if (*n == 0)
        {
            minwrk = 1;
            maxwrk = 1;
        }
        else
        {
            maxwrk = (*n << 1) + *n * ilaenv_(&c__1, "DGEHRD", " ", n, &c__1, n, &c__0);
            minwrk = *n * 3;
            dhseqr_("S", jobvs, n, &c__1, n, &a[a_offset], lda, &wr[1], &wi[1] , &vs[vs_offset], ldvs, &work[1], &c_n1, &ieval);
            hswork = (integer) work[1];
            if (! wantvs)
            {
                /* Computing MAX */
                i__1 = maxwrk;
                i__2 = *n + hswork; // , expr subst
                maxwrk = max(i__1,i__2);
            }
            else
            {
                /* Computing MAX */
                i__1 = maxwrk;
                i__2 = (*n << 1) + (*n - 1) * ilaenv_(&c__1, "DORGHR", " ", n, &c__1, n, &c_n1); // , expr subst
                maxwrk = max(i__1,i__2);
                /* Computing MAX */
                i__1 = maxwrk;
                i__2 = *n + hswork; // , expr subst
                maxwrk = max(i__1,i__2);
            }
        }
        work[1] = (doublereal) maxwrk;
        if (*lwork < minwrk && ! lquery)
        {
            *info = -13;
        }
    }
    if (*info != 0)
    {
        i__1 = -(*info);
        xerbla_("DGEES ", &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");
    smlnum = dlamch_("S");
    bignum = 1. / smlnum;
    dlabad_(&smlnum, &bignum);
    smlnum = sqrt(smlnum) / eps;
    bignum = 1. / smlnum;
    /* Scale A if max element outside range [SMLNUM,BIGNUM] */
    anrm = dlange_("M", n, n, &a[a_offset], lda, dum);
    scalea = FALSE_;
    if (anrm > 0. && anrm < smlnum)
    {
        scalea = TRUE_;
        cscale = smlnum;
    }
    else if (anrm > bignum)
    {
        scalea = TRUE_;
        cscale = bignum;
    }
    if (scalea)
    {
        dlascl_("G", &c__0, &c__0, &anrm, &cscale, n, n, &a[a_offset], lda, & ierr);
    }
    /* Permute the matrix to make it more nearly triangular */
    /* (Workspace: need N) */
    ibal = 1;
    dgebal_("P", n, &a[a_offset], lda, &ilo, &ihi, &work[ibal], &ierr);
    /* Reduce to upper Hessenberg form */
    /* (Workspace: need 3*N, prefer 2*N+N*NB) */
    itau = *n + ibal;
    iwrk = *n + itau;
    i__1 = *lwork - iwrk + 1;
    dgehrd_(n, &ilo, &ihi, &a[a_offset], lda, &work[itau], &work[iwrk], &i__1, &ierr);
    if (wantvs)
    {
        /* Copy Householder vectors to VS */
        dlacpy_("L", n, n, &a[a_offset], lda, &vs[vs_offset], ldvs) ;
        /* Generate orthogonal matrix in VS */
        /* (Workspace: need 3*N-1, prefer 2*N+(N-1)*NB) */
        i__1 = *lwork - iwrk + 1;
        dorghr_(n, &ilo, &ihi, &vs[vs_offset], ldvs, &work[itau], &work[iwrk], &i__1, &ierr);
    }
    *sdim = 0;
    /* Perform QR iteration, accumulating Schur vectors in VS if desired */
    /* (Workspace: need N+1, prefer N+HSWORK (see comments) ) */
    iwrk = itau;
    i__1 = *lwork - iwrk + 1;
    dhseqr_("S", jobvs, n, &ilo, &ihi, &a[a_offset], lda, &wr[1], &wi[1], &vs[ vs_offset], ldvs, &work[iwrk], &i__1, &ieval);
    if (ieval > 0)
    {
        *info = ieval;
    }
    /* Sort eigenvalues if desired */
    if (wantst && *info == 0)
    {
        if (scalea)
        {
            dlascl_("G", &c__0, &c__0, &cscale, &anrm, n, &c__1, &wr[1], n, & ierr);
            dlascl_("G", &c__0, &c__0, &cscale, &anrm, n, &c__1, &wi[1], n, & ierr);
        }
        i__1 = *n;
        for (i__ = 1;
                i__ <= i__1;
                ++i__)
        {
            bwork[i__] = (*select)(&wr[i__], &wi[i__]);
            /* L10: */
        }
        /* Reorder eigenvalues and transform Schur vectors */
        /* (Workspace: none needed) */
        i__1 = *lwork - iwrk + 1;
        dtrsen_("N", jobvs, &bwork[1], n, &a[a_offset], lda, &vs[vs_offset], ldvs, &wr[1], &wi[1], sdim, &s, &sep, &work[iwrk], &i__1, idum, &c__1, &icond);
        if (icond > 0)
        {
            *info = *n + icond;
        }
    }
    if (wantvs)
    {
        /* Undo balancing */
        /* (Workspace: need N) */
        dgebak_("P", "R", n, &ilo, &ihi, &work[ibal], n, &vs[vs_offset], ldvs, &ierr);
    }
    if (scalea)
    {
        /* Undo scaling for the Schur form of A */
        dlascl_("H", &c__0, &c__0, &cscale, &anrm, n, n, &a[a_offset], lda, & ierr);
        i__1 = *lda + 1;
        dcopy_(n, &a[a_offset], &i__1, &wr[1], &c__1);
        if (cscale == smlnum)
        {
            /* If scaling back towards underflow, adjust WI if an */
            /* offdiagonal element of a 2-by-2 block in the Schur form */
            /* underflows. */
            if (ieval > 0)
            {
                i1 = ieval + 1;
                i2 = ihi - 1;
                i__1 = ilo - 1;
                /* Computing MAX */
                i__3 = ilo - 1;
                i__2 = max(i__3,1);
                dlascl_("G", &c__0, &c__0, &cscale, &anrm, &i__1, &c__1, &wi[ 1], &i__2, &ierr);
            }
            else if (wantst)
            {
                i1 = 1;
                i2 = *n - 1;
            }
            else
            {
                i1 = ilo;
                i2 = ihi - 1;
            }
            inxt = i1 - 1;
            i__1 = i2;
            for (i__ = i1;
                    i__ <= i__1;
                    ++i__)
            {
                if (i__ < inxt)
                {
                    goto L20;
                }
                if (wi[i__] == 0.)
                {
                    inxt = i__ + 1;
                }
                else
                {
                    if (a[i__ + 1 + i__ * a_dim1] == 0.)
                    {
                        wi[i__] = 0.;
                        wi[i__ + 1] = 0.;
                    }
                    else if (a[i__ + 1 + i__ * a_dim1] != 0. && a[i__ + ( i__ + 1) * a_dim1] == 0.)
                    {
                        wi[i__] = 0.;
                        wi[i__ + 1] = 0.;
                        if (i__ > 1)
                        {
                            i__2 = i__ - 1;
                            dswap_(&i__2, &a[i__ * a_dim1 + 1], &c__1, &a[( i__ + 1) * a_dim1 + 1], &c__1);
                        }
                        if (*n > i__ + 1)
                        {
                            i__2 = *n - i__ - 1;
                            dswap_(&i__2, &a[i__ + (i__ + 2) * a_dim1], lda, & a[i__ + 1 + (i__ + 2) * a_dim1], lda);
                        }
                        if (wantvs)
                        {
                            dswap_(n, &vs[i__ * vs_dim1 + 1], &c__1, &vs[(i__ + 1) * vs_dim1 + 1], &c__1);
                        }
                        a[i__ + (i__ + 1) * a_dim1] = a[i__ + 1 + i__ * a_dim1];
                        a[i__ + 1 + i__ * a_dim1] = 0.;
                    }
                    inxt = i__ + 2;
                }
L20:
                ;
            }
        }
        /* Undo scaling for the imaginary part of the eigenvalues */
        i__1 = *n - ieval;
        /* Computing MAX */
        i__3 = *n - ieval;
        i__2 = max(i__3,1);
        dlascl_("G", &c__0, &c__0, &cscale, &anrm, &i__1, &c__1, &wi[ieval + 1], &i__2, &ierr);
    }
    if (wantst && *info == 0)
    {
        /* Check if reordering successful */
        lastsl = TRUE_;
        lst2sl = TRUE_;
        *sdim = 0;
        ip = 0;
        i__1 = *n;
        for (i__ = 1;
                i__ <= i__1;
                ++i__)
        {
            cursl = (*select)(&wr[i__], &wi[i__]);
            if (wi[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;
            /* L30: */
        }
    }
    work[1] = (doublereal) maxwrk;
    return 0;
    /* End of DGEES */
}