Provided by: liblapack-doc_3.11.0-2build1_all bug

NAME

       complex16GEcomputational - complex16

SYNOPSIS

   Functions
       subroutine zgebak (JOB, SIDE, N, ILO, IHI, SCALE, M, V, LDV, INFO)
           ZGEBAK
       subroutine zgebal (JOB, N, A, LDA, ILO, IHI, SCALE, INFO)
           ZGEBAL
       subroutine zgebd2 (M, N, A, LDA, D, E, TAUQ, TAUP, WORK, INFO)
           ZGEBD2 reduces a general matrix to bidiagonal form using an unblocked algorithm.
       subroutine zgebrd (M, N, A, LDA, D, E, TAUQ, TAUP, WORK, LWORK, INFO)
           ZGEBRD
       subroutine zgecon (NORM, N, A, LDA, ANORM, RCOND, WORK, RWORK, INFO)
           ZGECON
       subroutine zgeequ (M, N, A, LDA, R, C, ROWCND, COLCND, AMAX, INFO)
           ZGEEQU
       subroutine zgeequb (M, N, A, LDA, R, C, ROWCND, COLCND, AMAX, INFO)
           ZGEEQUB
       subroutine zgehd2 (N, ILO, IHI, A, LDA, TAU, WORK, INFO)
           ZGEHD2 reduces a general square matrix to upper Hessenberg form using an unblocked
           algorithm.
       subroutine zgehrd (N, ILO, IHI, A, LDA, TAU, WORK, LWORK, INFO)
           ZGEHRD
       subroutine zgelq2 (M, N, A, LDA, TAU, WORK, INFO)
           ZGELQ2 computes the LQ factorization of a general rectangular matrix using an
           unblocked algorithm.
       subroutine zgelqf (M, N, A, LDA, TAU, WORK, LWORK, INFO)
           ZGELQF
       subroutine zgemqrt (SIDE, TRANS, M, N, K, NB, V, LDV, T, LDT, C, LDC, WORK, INFO)
           ZGEMQRT
       subroutine zgeql2 (M, N, A, LDA, TAU, WORK, INFO)
           ZGEQL2 computes the QL factorization of a general rectangular matrix using an
           unblocked algorithm.
       subroutine zgeqlf (M, N, A, LDA, TAU, WORK, LWORK, INFO)
           ZGEQLF
       subroutine zgeqp3 (M, N, A, LDA, JPVT, TAU, WORK, LWORK, RWORK, INFO)
           ZGEQP3
       subroutine zgeqr2 (M, N, A, LDA, TAU, WORK, INFO)
           ZGEQR2 computes the QR factorization of a general rectangular matrix using an
           unblocked algorithm.
       subroutine zgeqr2p (M, N, A, LDA, TAU, WORK, INFO)
           ZGEQR2P computes the QR factorization of a general rectangular matrix with non-
           negative diagonal elements using an unblocked algorithm.
       subroutine zgeqrf (M, N, A, LDA, TAU, WORK, LWORK, INFO)
           ZGEQRF
       subroutine zgeqrfp (M, N, A, LDA, TAU, WORK, LWORK, INFO)
           ZGEQRFP
       subroutine zgeqrt (M, N, NB, A, LDA, T, LDT, WORK, INFO)
           ZGEQRT
       subroutine zgeqrt2 (M, N, A, LDA, T, LDT, INFO)
           ZGEQRT2 computes a QR factorization of a general real or complex matrix using the
           compact WY representation of Q.
       recursive subroutine zgeqrt3 (M, N, A, LDA, T, LDT, INFO)
           ZGEQRT3 recursively computes a QR factorization of a general real or complex matrix
           using the compact WY representation of Q.
       subroutine zgerfs (TRANS, N, NRHS, A, LDA, AF, LDAF, IPIV, B, LDB, X, LDX, FERR, BERR,
           WORK, RWORK, INFO)
           ZGERFS
       subroutine zgerfsx (TRANS, EQUED, N, NRHS, A, LDA, AF, LDAF, IPIV, R, C, B, LDB, X, LDX,
           RCOND, BERR, N_ERR_BNDS, ERR_BNDS_NORM, ERR_BNDS_COMP, NPARAMS, PARAMS, WORK, RWORK,
           INFO)
           ZGERFSX
       subroutine zgerq2 (M, N, A, LDA, TAU, WORK, INFO)
           ZGERQ2 computes the RQ factorization of a general rectangular matrix using an
           unblocked algorithm.
       subroutine zgerqf (M, N, A, LDA, TAU, WORK, LWORK, INFO)
           ZGERQF
       subroutine zgesvj (JOBA, JOBU, JOBV, M, N, A, LDA, SVA, MV, V, LDV, CWORK, LWORK, RWORK,
           LRWORK, INFO)
            ZGESVJ
       subroutine zgetf2 (M, N, A, LDA, IPIV, INFO)
           ZGETF2 computes the LU factorization of a general m-by-n matrix using partial pivoting
           with row interchanges (unblocked algorithm).
       subroutine zgetrf (M, N, A, LDA, IPIV, INFO)
           ZGETRF
       recursive subroutine zgetrf2 (M, N, A, LDA, IPIV, INFO)
           ZGETRF2
       subroutine zgetri (N, A, LDA, IPIV, WORK, LWORK, INFO)
           ZGETRI
       subroutine zgetrs (TRANS, N, NRHS, A, LDA, IPIV, B, LDB, INFO)
           ZGETRS
       subroutine zhgeqz (JOB, COMPQ, COMPZ, N, ILO, IHI, H, LDH, T, LDT, ALPHA, BETA, Q, LDQ, Z,
           LDZ, WORK, LWORK, RWORK, INFO)
           ZHGEQZ
       subroutine zla_geamv (TRANS, M, N, ALPHA, A, LDA, X, INCX, BETA, Y, INCY)
           ZLA_GEAMV computes a matrix-vector product using a general matrix to calculate error
           bounds.
       double precision function zla_gercond_c (TRANS, N, A, LDA, AF, LDAF, IPIV, C, CAPPLY,
           INFO, WORK, RWORK)
           ZLA_GERCOND_C computes the infinity norm condition number of op(A)*inv(diag(c)) for
           general matrices.
       double precision function zla_gercond_x (TRANS, N, A, LDA, AF, LDAF, IPIV, X, INFO, WORK,
           RWORK)
           ZLA_GERCOND_X computes the infinity norm condition number of op(A)*diag(x) for general
           matrices.
       subroutine zla_gerfsx_extended (PREC_TYPE, TRANS_TYPE, N, NRHS, A, LDA, AF, LDAF, IPIV,
           COLEQU, C, B, LDB, Y, LDY, BERR_OUT, N_NORMS, ERRS_N, ERRS_C, RES, AYB, DY, Y_TAIL,
           RCOND, ITHRESH, RTHRESH, DZ_UB, IGNORE_CWISE, INFO)
           ZLA_GERFSX_EXTENDED
       double precision function zla_gerpvgrw (N, NCOLS, A, LDA, AF, LDAF)
           ZLA_GERPVGRW multiplies a square real matrix by a complex matrix.
       recursive subroutine zlaqz0 (WANTS, WANTQ, WANTZ, N, ILO, IHI, A, LDA, B, LDB, ALPHA,
           BETA, Q, LDQ, Z, LDZ, WORK, LWORK, RWORK, REC, INFO)
           ZLAQZ0
       subroutine zlaqz1 (ILQ, ILZ, K, ISTARTM, ISTOPM, IHI, A, LDA, B, LDB, NQ, QSTART, Q, LDQ,
           NZ, ZSTART, Z, LDZ)
           ZLAQZ1
       recursive subroutine zlaqz2 (ILSCHUR, ILQ, ILZ, N, ILO, IHI, NW, A, LDA, B, LDB, Q, LDQ,
           Z, LDZ, NS, ND, ALPHA, BETA, QC, LDQC, ZC, LDZC, WORK, LWORK, RWORK, REC, INFO)
           ZLAQZ2
       subroutine zlaqz3 (ILSCHUR, ILQ, ILZ, N, ILO, IHI, NSHIFTS, NBLOCK_DESIRED, ALPHA, BETA,
           A, LDA, B, LDB, Q, LDQ, Z, LDZ, QC, LDQC, ZC, LDZC, WORK, LWORK, INFO)
           ZLAQZ3
       subroutine zlaunhr_col_getrfnp (M, N, A, LDA, D, INFO)
           ZLAUNHR_COL_GETRFNP
       recursive subroutine zlaunhr_col_getrfnp2 (M, N, A, LDA, D, INFO)
           ZLAUNHR_COL_GETRFNP2
       subroutine ztgevc (SIDE, HOWMNY, SELECT, N, S, LDS, P, LDP, VL, LDVL, VR, LDVR, MM, M,
           WORK, RWORK, INFO)
           ZTGEVC
       subroutine ztgexc (WANTQ, WANTZ, N, A, LDA, B, LDB, Q, LDQ, Z, LDZ, IFST, ILST, INFO)
           ZTGEXC

Detailed Description

       This is the group of complex16 computational functions for GE matrices

Function Documentation

   subroutine zgebak (character JOB, character SIDE, integer N, integer ILO, integer IHI, double
       precision, dimension( * ) SCALE, integer M, complex*16, dimension( ldv, * ) V, integer
       LDV, integer INFO)
       ZGEBAK

       Purpose:

            ZGEBAK forms the right or left eigenvectors of a complex general
            matrix by backward transformation on the computed eigenvectors of the
            balanced matrix output by ZGEBAL.

       Parameters
           JOB

                     JOB is CHARACTER*1
                     Specifies the type of backward transformation required:
                     = 'N': do nothing, return immediately;
                     = 'P': do backward transformation for permutation only;
                     = 'S': do backward transformation for scaling only;
                     = 'B': do backward transformations for both permutation and
                            scaling.
                     JOB must be the same as the argument JOB supplied to ZGEBAL.

           SIDE

                     SIDE is CHARACTER*1
                     = 'R':  V contains right eigenvectors;
                     = 'L':  V contains left eigenvectors.

           N

                     N is INTEGER
                     The number of rows of the matrix V.  N >= 0.

           ILO

                     ILO is INTEGER

           IHI

                     IHI is INTEGER
                     The integers ILO and IHI determined by ZGEBAL.
                     1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0.

           SCALE

                     SCALE is DOUBLE PRECISION array, dimension (N)
                     Details of the permutation and scaling factors, as returned
                     by ZGEBAL.

           M

                     M is INTEGER
                     The number of columns of the matrix V.  M >= 0.

           V

                     V is COMPLEX*16 array, dimension (LDV,M)
                     On entry, the matrix of right or left eigenvectors to be
                     transformed, as returned by ZHSEIN or ZTREVC.
                     On exit, V is overwritten by the transformed eigenvectors.

           LDV

                     LDV is INTEGER
                     The leading dimension of the array V. LDV >= max(1,N).

           INFO

                     INFO is INTEGER
                     = 0:  successful exit
                     < 0:  if INFO = -i, the i-th argument had an illegal value.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

   subroutine zgebal (character JOB, integer N, complex*16, dimension( lda, * ) A, integer LDA,
       integer ILO, integer IHI, double precision, dimension( * ) SCALE, integer INFO)
       ZGEBAL

       Purpose:

            ZGEBAL balances a general complex matrix A.  This involves, first,
            permuting A by a similarity transformation to isolate eigenvalues
            in the first 1 to ILO-1 and last IHI+1 to N elements on the
            diagonal; and second, applying a diagonal similarity transformation
            to rows and columns ILO to IHI to make the rows and columns as
            close in norm as possible.  Both steps are optional.

            Balancing may reduce the 1-norm of the matrix, and improve the
            accuracy of the computed eigenvalues and/or eigenvectors.

       Parameters
           JOB

                     JOB is CHARACTER*1
                     Specifies the operations to be performed on A:
                     = 'N':  none:  simply set ILO = 1, IHI = N, SCALE(I) = 1.0
                             for i = 1,...,N;
                     = 'P':  permute only;
                     = 'S':  scale only;
                     = 'B':  both permute and scale.

           N

                     N is INTEGER
                     The order of the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the input matrix A.
                     On exit,  A is overwritten by the balanced matrix.
                     If JOB = 'N', A is not referenced.
                     See Further Details.

           LDA

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

           ILO

                     ILO is INTEGER

           IHI

                     IHI is INTEGER
                     ILO and IHI are set to INTEGER such that on exit
                     A(i,j) = 0 if i > j and j = 1,...,ILO-1 or I = IHI+1,...,N.
                     If JOB = 'N' or 'S', ILO = 1 and IHI = N.

           SCALE

                     SCALE is DOUBLE PRECISION array, dimension (N)
                     Details of the permutations and scaling factors applied to
                     A.  If P(j) is the index of the row and column interchanged
                     with row and column j and D(j) is the scaling factor
                     applied to row and column j, then
                     SCALE(j) = P(j)    for j = 1,...,ILO-1
                              = D(j)    for j = ILO,...,IHI
                              = P(j)    for j = IHI+1,...,N.
                     The order in which the interchanges are made is N to IHI+1,
                     then 1 to ILO-1.

           INFO

                     INFO is INTEGER
                     = 0:  successful exit.
                     < 0:  if INFO = -i, the i-th argument had an illegal value.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             The permutations consist of row and column interchanges which put
             the matrix in the form

                        ( T1   X   Y  )
                P A P = (  0   B   Z  )
                        (  0   0   T2 )

             where T1 and T2 are upper triangular matrices whose eigenvalues lie
             along the diagonal.  The column indices ILO and IHI mark the starting
             and ending columns of the submatrix B. Balancing consists of applying
             a diagonal similarity transformation inv(D) * B * D to make the
             1-norms of each row of B and its corresponding column nearly equal.
             The output matrix is

                ( T1     X*D          Y    )
                (  0  inv(D)*B*D  inv(D)*Z ).
                (  0      0           T2   )

             Information about the permutations P and the diagonal matrix D is
             returned in the vector SCALE.

             This subroutine is based on the EISPACK routine CBAL.

             Modified by Tzu-Yi Chen, Computer Science Division, University of
               California at Berkeley, USA

   subroutine zgebd2 (integer M, integer N, complex*16, dimension( lda, * ) A, integer LDA,
       double precision, dimension( * ) D, double precision, dimension( * ) E, complex*16,
       dimension( * ) TAUQ, complex*16, dimension( * ) TAUP, complex*16, dimension( * ) WORK,
       integer INFO)
       ZGEBD2 reduces a general matrix to bidiagonal form using an unblocked algorithm.

       Purpose:

            ZGEBD2 reduces a complex general m by n matrix A to upper or lower
            real bidiagonal form B by a unitary transformation: Q**H * A * P = B.

            If m >= n, B is upper bidiagonal; if m < n, B is lower bidiagonal.

       Parameters
           M

                     M is INTEGER
                     The number of rows in the matrix A.  M >= 0.

           N

                     N is INTEGER
                     The number of columns in the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the m by n general matrix to be reduced.
                     On exit,
                     if m >= n, the diagonal and the first superdiagonal are
                       overwritten with the upper bidiagonal matrix B; the
                       elements below the diagonal, with the array TAUQ, represent
                       the unitary matrix Q as a product of elementary
                       reflectors, and the elements above the first superdiagonal,
                       with the array TAUP, represent the unitary matrix P as
                       a product of elementary reflectors;
                     if m < n, the diagonal and the first subdiagonal are
                       overwritten with the lower bidiagonal matrix B; the
                       elements below the first subdiagonal, with the array TAUQ,
                       represent the unitary matrix Q as a product of
                       elementary reflectors, and the elements above the diagonal,
                       with the array TAUP, represent the unitary matrix P as
                       a product of elementary reflectors.
                     See Further Details.

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,M).

           D

                     D is DOUBLE PRECISION array, dimension (min(M,N))
                     The diagonal elements of the bidiagonal matrix B:
                     D(i) = A(i,i).

           E

                     E is DOUBLE PRECISION array, dimension (min(M,N)-1)
                     The off-diagonal elements of the bidiagonal matrix B:
                     if m >= n, E(i) = A(i,i+1) for i = 1,2,...,n-1;
                     if m < n, E(i) = A(i+1,i) for i = 1,2,...,m-1.

           TAUQ

                     TAUQ is COMPLEX*16 array, dimension (min(M,N))
                     The scalar factors of the elementary reflectors which
                     represent the unitary matrix Q. See Further Details.

           TAUP

                     TAUP is COMPLEX*16 array, dimension (min(M,N))
                     The scalar factors of the elementary reflectors which
                     represent the unitary matrix P. See Further Details.

           WORK

                     WORK is COMPLEX*16 array, dimension (max(M,N))

           INFO

                     INFO is INTEGER
                     = 0: successful exit
                     < 0: if INFO = -i, the i-th argument had an illegal value.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             The matrices Q and P are represented as products of elementary
             reflectors:

             If m >= n,

                Q = H(1) H(2) . . . H(n)  and  P = G(1) G(2) . . . G(n-1)

             Each H(i) and G(i) has the form:

                H(i) = I - tauq * v * v**H  and G(i) = I - taup * u * u**H

             where tauq and taup are complex scalars, and v and u are complex
             vectors; v(1:i-1) = 0, v(i) = 1, and v(i+1:m) is stored on exit in
             A(i+1:m,i); u(1:i) = 0, u(i+1) = 1, and u(i+2:n) is stored on exit in
             A(i,i+2:n); tauq is stored in TAUQ(i) and taup in TAUP(i).

             If m < n,

                Q = H(1) H(2) . . . H(m-1)  and  P = G(1) G(2) . . . G(m)

             Each H(i) and G(i) has the form:

                H(i) = I - tauq * v * v**H  and G(i) = I - taup * u * u**H

             where tauq and taup are complex scalars, v and u are complex vectors;
             v(1:i) = 0, v(i+1) = 1, and v(i+2:m) is stored on exit in A(i+2:m,i);
             u(1:i-1) = 0, u(i) = 1, and u(i+1:n) is stored on exit in A(i,i+1:n);
             tauq is stored in TAUQ(i) and taup in TAUP(i).

             The contents of A on exit are illustrated by the following examples:

             m = 6 and n = 5 (m > n):          m = 5 and n = 6 (m < n):

               (  d   e   u1  u1  u1 )           (  d   u1  u1  u1  u1  u1 )
               (  v1  d   e   u2  u2 )           (  e   d   u2  u2  u2  u2 )
               (  v1  v2  d   e   u3 )           (  v1  e   d   u3  u3  u3 )
               (  v1  v2  v3  d   e  )           (  v1  v2  e   d   u4  u4 )
               (  v1  v2  v3  v4  d  )           (  v1  v2  v3  e   d   u5 )
               (  v1  v2  v3  v4  v5 )

             where d and e denote diagonal and off-diagonal elements of B, vi
             denotes an element of the vector defining H(i), and ui an element of
             the vector defining G(i).

   subroutine zgebrd (integer M, integer N, complex*16, dimension( lda, * ) A, integer LDA,
       double precision, dimension( * ) D, double precision, dimension( * ) E, complex*16,
       dimension( * ) TAUQ, complex*16, dimension( * ) TAUP, complex*16, dimension( * ) WORK,
       integer LWORK, integer INFO)
       ZGEBRD

       Purpose:

            ZGEBRD reduces a general complex M-by-N matrix A to upper or lower
            bidiagonal form B by a unitary transformation: Q**H * A * P = B.

            If m >= n, B is upper bidiagonal; if m < n, B is lower bidiagonal.

       Parameters
           M

                     M is INTEGER
                     The number of rows in the matrix A.  M >= 0.

           N

                     N is INTEGER
                     The number of columns in the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the M-by-N general matrix to be reduced.
                     On exit,
                     if m >= n, the diagonal and the first superdiagonal are
                       overwritten with the upper bidiagonal matrix B; the
                       elements below the diagonal, with the array TAUQ, represent
                       the unitary matrix Q as a product of elementary
                       reflectors, and the elements above the first superdiagonal,
                       with the array TAUP, represent the unitary matrix P as
                       a product of elementary reflectors;
                     if m < n, the diagonal and the first subdiagonal are
                       overwritten with the lower bidiagonal matrix B; the
                       elements below the first subdiagonal, with the array TAUQ,
                       represent the unitary matrix Q as a product of
                       elementary reflectors, and the elements above the diagonal,
                       with the array TAUP, represent the unitary matrix P as
                       a product of elementary reflectors.
                     See Further Details.

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,M).

           D

                     D is DOUBLE PRECISION array, dimension (min(M,N))
                     The diagonal elements of the bidiagonal matrix B:
                     D(i) = A(i,i).

           E

                     E is DOUBLE PRECISION array, dimension (min(M,N)-1)
                     The off-diagonal elements of the bidiagonal matrix B:
                     if m >= n, E(i) = A(i,i+1) for i = 1,2,...,n-1;
                     if m < n, E(i) = A(i+1,i) for i = 1,2,...,m-1.

           TAUQ

                     TAUQ is COMPLEX*16 array, dimension (min(M,N))
                     The scalar factors of the elementary reflectors which
                     represent the unitary matrix Q. See Further Details.

           TAUP

                     TAUP is COMPLEX*16 array, dimension (min(M,N))
                     The scalar factors of the elementary reflectors which
                     represent the unitary matrix P. See Further Details.

           WORK

                     WORK is COMPLEX*16 array, dimension (MAX(1,LWORK))
                     On exit, if INFO = 0, WORK(1) returns the optimal LWORK.

           LWORK

                     LWORK is INTEGER
                     The length of the array WORK.  LWORK >= max(1,M,N).
                     For optimum performance LWORK >= (M+N)*NB, where NB
                     is the optimal blocksize.

                     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.

           INFO

                     INFO is INTEGER
                     = 0:  successful exit.
                     < 0:  if INFO = -i, the i-th argument had an illegal value.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             The matrices Q and P are represented as products of elementary
             reflectors:

             If m >= n,

                Q = H(1) H(2) . . . H(n)  and  P = G(1) G(2) . . . G(n-1)

             Each H(i) and G(i) has the form:

                H(i) = I - tauq * v * v**H  and G(i) = I - taup * u * u**H

             where tauq and taup are complex scalars, and v and u are complex
             vectors; v(1:i-1) = 0, v(i) = 1, and v(i+1:m) is stored on exit in
             A(i+1:m,i); u(1:i) = 0, u(i+1) = 1, and u(i+2:n) is stored on exit in
             A(i,i+2:n); tauq is stored in TAUQ(i) and taup in TAUP(i).

             If m < n,

                Q = H(1) H(2) . . . H(m-1)  and  P = G(1) G(2) . . . G(m)

             Each H(i) and G(i) has the form:

                H(i) = I - tauq * v * v**H  and G(i) = I - taup * u * u**H

             where tauq and taup are complex scalars, and v and u are complex
             vectors; v(1:i) = 0, v(i+1) = 1, and v(i+2:m) is stored on exit in
             A(i+2:m,i); u(1:i-1) = 0, u(i) = 1, and u(i+1:n) is stored on exit in
             A(i,i+1:n); tauq is stored in TAUQ(i) and taup in TAUP(i).

             The contents of A on exit are illustrated by the following examples:

             m = 6 and n = 5 (m > n):          m = 5 and n = 6 (m < n):

               (  d   e   u1  u1  u1 )           (  d   u1  u1  u1  u1  u1 )
               (  v1  d   e   u2  u2 )           (  e   d   u2  u2  u2  u2 )
               (  v1  v2  d   e   u3 )           (  v1  e   d   u3  u3  u3 )
               (  v1  v2  v3  d   e  )           (  v1  v2  e   d   u4  u4 )
               (  v1  v2  v3  v4  d  )           (  v1  v2  v3  e   d   u5 )
               (  v1  v2  v3  v4  v5 )

             where d and e denote diagonal and off-diagonal elements of B, vi
             denotes an element of the vector defining H(i), and ui an element of
             the vector defining G(i).

   subroutine zgecon (character NORM, integer N, complex*16, dimension( lda, * ) A, integer LDA,
       double precision ANORM, double precision RCOND, complex*16, dimension( * ) WORK, double
       precision, dimension( * ) RWORK, integer INFO)
       ZGECON

       Purpose:

            ZGECON estimates the reciprocal of the condition number of a general
            complex matrix A, in either the 1-norm or the infinity-norm, using
            the LU factorization computed by ZGETRF.

            An estimate is obtained for norm(inv(A)), and the reciprocal of the
            condition number is computed as
               RCOND = 1 / ( norm(A) * norm(inv(A)) ).

       Parameters
           NORM

                     NORM is CHARACTER*1
                     Specifies whether the 1-norm condition number or the
                     infinity-norm condition number is required:
                     = '1' or 'O':  1-norm;
                     = 'I':         Infinity-norm.

           N

                     N is INTEGER
                     The order of the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     The factors L and U from the factorization A = P*L*U
                     as computed by ZGETRF.

           LDA

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

           ANORM

                     ANORM is DOUBLE PRECISION
                     If NORM = '1' or 'O', the 1-norm of the original matrix A.
                     If NORM = 'I', the infinity-norm of the original matrix A.

           RCOND

                     RCOND is DOUBLE PRECISION
                     The reciprocal of the condition number of the matrix A,
                     computed as RCOND = 1/(norm(A) * norm(inv(A))).

           WORK

                     WORK is COMPLEX*16 array, dimension (2*N)

           RWORK

                     RWORK is DOUBLE PRECISION array, dimension (2*N)

           INFO

                     INFO is INTEGER
                     = 0:  successful exit
                     < 0:  if INFO = -i, the i-th argument had an illegal value

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

   subroutine zgeequ (integer M, integer N, complex*16, dimension( lda, * ) A, integer LDA,
       double precision, dimension( * ) R, double precision, dimension( * ) C, double precision
       ROWCND, double precision COLCND, double precision AMAX, integer INFO)
       ZGEEQU

       Purpose:

            ZGEEQU computes row and column scalings intended to equilibrate an
            M-by-N matrix A and reduce its condition number.  R returns the row
            scale factors and C the column scale factors, chosen to try to make
            the largest element in each row and column of the matrix B with
            elements B(i,j)=R(i)*A(i,j)*C(j) have absolute value 1.

            R(i) and C(j) are restricted to be between SMLNUM = smallest safe
            number and BIGNUM = largest safe number.  Use of these scaling
            factors is not guaranteed to reduce the condition number of A but
            works well in practice.

       Parameters
           M

                     M is INTEGER
                     The number of rows of the matrix A.  M >= 0.

           N

                     N is INTEGER
                     The number of columns of the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     The M-by-N matrix whose equilibration factors are
                     to be computed.

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,M).

           R

                     R is DOUBLE PRECISION array, dimension (M)
                     If INFO = 0 or INFO > M, R contains the row scale factors
                     for A.

           C

                     C is DOUBLE PRECISION array, dimension (N)
                     If INFO = 0,  C contains the column scale factors for A.

           ROWCND

                     ROWCND is DOUBLE PRECISION
                     If INFO = 0 or INFO > M, ROWCND contains the ratio of the
                     smallest R(i) to the largest R(i).  If ROWCND >= 0.1 and
                     AMAX is neither too large nor too small, it is not worth
                     scaling by R.

           COLCND

                     COLCND is DOUBLE PRECISION
                     If INFO = 0, COLCND contains the ratio of the smallest
                     C(i) to the largest C(i).  If COLCND >= 0.1, it is not
                     worth scaling by C.

           AMAX

                     AMAX is DOUBLE PRECISION
                     Absolute value of largest matrix element.  If AMAX is very
                     close to overflow or very close to underflow, the matrix
                     should be scaled.

           INFO

                     INFO is INTEGER
                     = 0:  successful exit
                     < 0:  if INFO = -i, the i-th argument had an illegal value
                     > 0:  if INFO = i,  and i is
                           <= M:  the i-th row of A is exactly zero
                           >  M:  the (i-M)-th column of A is exactly zero

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

   subroutine zgeequb (integer M, integer N, complex*16, dimension( lda, * ) A, integer LDA,
       double precision, dimension( * ) R, double precision, dimension( * ) C, double precision
       ROWCND, double precision COLCND, double precision AMAX, integer INFO)
       ZGEEQUB

       Purpose:

            ZGEEQUB computes row and column scalings intended to equilibrate an
            M-by-N matrix A and reduce its condition number.  R returns the row
            scale factors and C the column scale factors, chosen to try to make
            the largest element in each row and column of the matrix B with
            elements B(i,j)=R(i)*A(i,j)*C(j) have an absolute value of at most
            the radix.

            R(i) and C(j) are restricted to be a power of the radix between
            SMLNUM = smallest safe number and BIGNUM = largest safe number.  Use
            of these scaling factors is not guaranteed to reduce the condition
            number of A but works well in practice.

            This routine differs from ZGEEQU by restricting the scaling factors
            to a power of the radix.  Barring over- and underflow, scaling by
            these factors introduces no additional rounding errors.  However, the
            scaled entries' magnitudes are no longer approximately 1 but lie
            between sqrt(radix) and 1/sqrt(radix).

       Parameters
           M

                     M is INTEGER
                     The number of rows of the matrix A.  M >= 0.

           N

                     N is INTEGER
                     The number of columns of the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     The M-by-N matrix whose equilibration factors are
                     to be computed.

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,M).

           R

                     R is DOUBLE PRECISION array, dimension (M)
                     If INFO = 0 or INFO > M, R contains the row scale factors
                     for A.

           C

                     C is DOUBLE PRECISION array, dimension (N)
                     If INFO = 0,  C contains the column scale factors for A.

           ROWCND

                     ROWCND is DOUBLE PRECISION
                     If INFO = 0 or INFO > M, ROWCND contains the ratio of the
                     smallest R(i) to the largest R(i).  If ROWCND >= 0.1 and
                     AMAX is neither too large nor too small, it is not worth
                     scaling by R.

           COLCND

                     COLCND is DOUBLE PRECISION
                     If INFO = 0, COLCND contains the ratio of the smallest
                     C(i) to the largest C(i).  If COLCND >= 0.1, it is not
                     worth scaling by C.

           AMAX

                     AMAX is DOUBLE PRECISION
                     Absolute value of largest matrix element.  If AMAX is very
                     close to overflow or very close to underflow, the matrix
                     should be scaled.

           INFO

                     INFO is INTEGER
                     = 0:  successful exit
                     < 0:  if INFO = -i, the i-th argument had an illegal value
                     > 0:  if INFO = i,  and i is
                           <= M:  the i-th row of A is exactly zero
                           >  M:  the (i-M)-th column of A is exactly zero

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

   subroutine zgehd2 (integer N, integer ILO, integer IHI, complex*16, dimension( lda, * ) A,
       integer LDA, complex*16, dimension( * ) TAU, complex*16, dimension( * ) WORK, integer
       INFO)
       ZGEHD2 reduces a general square matrix to upper Hessenberg form using an unblocked
       algorithm.

       Purpose:

            ZGEHD2 reduces a complex general matrix A to upper Hessenberg form H
            by a unitary similarity transformation:  Q**H * A * Q = H .

       Parameters
           N

                     N is INTEGER
                     The order of the matrix A.  N >= 0.

           ILO

                     ILO is INTEGER

           IHI

                     IHI is INTEGER

                     It is assumed that A is already upper triangular in rows
                     and columns 1:ILO-1 and IHI+1:N. ILO and IHI are normally
                     set by a previous call to ZGEBAL; otherwise they should be
                     set to 1 and N respectively. See Further Details.
                     1 <= ILO <= IHI <= max(1,N).

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the n by n general matrix to be reduced.
                     On exit, the upper triangle and the first subdiagonal of A
                     are overwritten with the upper Hessenberg matrix H, and the
                     elements below the first subdiagonal, with the array TAU,
                     represent the unitary matrix Q as a product of elementary
                     reflectors. See Further Details.

           LDA

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

           TAU

                     TAU is COMPLEX*16 array, dimension (N-1)
                     The scalar factors of the elementary reflectors (see Further
                     Details).

           WORK

                     WORK is COMPLEX*16 array, dimension (N)

           INFO

                     INFO is INTEGER
                     = 0:  successful exit
                     < 0:  if INFO = -i, the i-th argument had an illegal value.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             The matrix Q is represented as a product of (ihi-ilo) elementary
             reflectors

                Q = H(ilo) H(ilo+1) . . . H(ihi-1).

             Each H(i) has the form

                H(i) = I - tau * v * v**H

             where tau is a complex scalar, and v is a complex vector with
             v(1:i) = 0, v(i+1) = 1 and v(ihi+1:n) = 0; v(i+2:ihi) is stored on
             exit in A(i+2:ihi,i), and tau in TAU(i).

             The contents of A are illustrated by the following example, with
             n = 7, ilo = 2 and ihi = 6:

             on entry,                        on exit,

             ( a   a   a   a   a   a   a )    (  a   a   h   h   h   h   a )
             (     a   a   a   a   a   a )    (      a   h   h   h   h   a )
             (     a   a   a   a   a   a )    (      h   h   h   h   h   h )
             (     a   a   a   a   a   a )    (      v2  h   h   h   h   h )
             (     a   a   a   a   a   a )    (      v2  v3  h   h   h   h )
             (     a   a   a   a   a   a )    (      v2  v3  v4  h   h   h )
             (                         a )    (                          a )

             where a denotes an element of the original matrix A, h denotes a
             modified element of the upper Hessenberg matrix H, and vi denotes an
             element of the vector defining H(i).

   subroutine zgehrd (integer N, integer ILO, integer IHI, complex*16, dimension( lda, * ) A,
       integer LDA, complex*16, dimension( * ) TAU, complex*16, dimension( * ) WORK, integer
       LWORK, integer INFO)
       ZGEHRD

       Purpose:

            ZGEHRD reduces a complex general matrix A to upper Hessenberg form H by
            an unitary similarity transformation:  Q**H * A * Q = H .

       Parameters
           N

                     N is INTEGER
                     The order of the matrix A.  N >= 0.

           ILO

                     ILO is INTEGER

           IHI

                     IHI is INTEGER

                     It is assumed that A is already upper triangular in rows
                     and columns 1:ILO-1 and IHI+1:N. ILO and IHI are normally
                     set by a previous call to ZGEBAL; otherwise they should be
                     set to 1 and N respectively. See Further Details.
                     1 <= ILO <= IHI <= N, if N > 0; ILO=1 and IHI=0, if N=0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the N-by-N general matrix to be reduced.
                     On exit, the upper triangle and the first subdiagonal of A
                     are overwritten with the upper Hessenberg matrix H, and the
                     elements below the first subdiagonal, with the array TAU,
                     represent the unitary matrix Q as a product of elementary
                     reflectors. See Further Details.

           LDA

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

           TAU

                     TAU is COMPLEX*16 array, dimension (N-1)
                     The scalar factors of the elementary reflectors (see Further
                     Details). Elements 1:ILO-1 and IHI:N-1 of TAU are set to
                     zero.

           WORK

                     WORK is COMPLEX*16 array, dimension (LWORK)
                     On exit, if INFO = 0, WORK(1) returns the optimal LWORK.

           LWORK

                     LWORK is INTEGER
                     The length of the array WORK.  LWORK >= max(1,N).
                     For good performance, LWORK should 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.

           INFO

                     INFO is INTEGER
                     = 0:  successful exit
                     < 0:  if INFO = -i, the i-th argument had an illegal value.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             The matrix Q is represented as a product of (ihi-ilo) elementary
             reflectors

                Q = H(ilo) H(ilo+1) . . . H(ihi-1).

             Each H(i) has the form

                H(i) = I - tau * v * v**H

             where tau is a complex scalar, and v is a complex vector with
             v(1:i) = 0, v(i+1) = 1 and v(ihi+1:n) = 0; v(i+2:ihi) is stored on
             exit in A(i+2:ihi,i), and tau in TAU(i).

             The contents of A are illustrated by the following example, with
             n = 7, ilo = 2 and ihi = 6:

             on entry,                        on exit,

             ( a   a   a   a   a   a   a )    (  a   a   h   h   h   h   a )
             (     a   a   a   a   a   a )    (      a   h   h   h   h   a )
             (     a   a   a   a   a   a )    (      h   h   h   h   h   h )
             (     a   a   a   a   a   a )    (      v2  h   h   h   h   h )
             (     a   a   a   a   a   a )    (      v2  v3  h   h   h   h )
             (     a   a   a   a   a   a )    (      v2  v3  v4  h   h   h )
             (                         a )    (                          a )

             where a denotes an element of the original matrix A, h denotes a
             modified element of the upper Hessenberg matrix H, and vi denotes an
             element of the vector defining H(i).

             This file is a slight modification of LAPACK-3.0's ZGEHRD
             subroutine incorporating improvements proposed by Quintana-Orti and
             Van de Geijn (2006). (See ZLAHR2.)

   subroutine zgelq2 (integer M, integer N, complex*16, dimension( lda, * ) A, integer LDA,
       complex*16, dimension( * ) TAU, complex*16, dimension( * ) WORK, integer INFO)
       ZGELQ2 computes the LQ factorization of a general rectangular matrix using an unblocked
       algorithm.

       Purpose:

            ZGELQ2 computes an LQ factorization of a complex m-by-n matrix A:

               A = ( L 0 ) *  Q

            where:

               Q is a n-by-n orthogonal matrix;
               L is a lower-triangular m-by-m matrix;
               0 is a m-by-(n-m) zero matrix, if m < n.

       Parameters
           M

                     M is INTEGER
                     The number of rows of the matrix A.  M >= 0.

           N

                     N is INTEGER
                     The number of columns of the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the m by n matrix A.
                     On exit, the elements on and below the diagonal of the array
                     contain the m by min(m,n) lower trapezoidal matrix L (L is
                     lower triangular if m <= n); the elements above the diagonal,
                     with the array TAU, represent the unitary matrix Q as a
                     product of elementary reflectors (see Further Details).

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,M).

           TAU

                     TAU is COMPLEX*16 array, dimension (min(M,N))
                     The scalar factors of the elementary reflectors (see Further
                     Details).

           WORK

                     WORK is COMPLEX*16 array, dimension (M)

           INFO

                     INFO is INTEGER
                     = 0: successful exit
                     < 0: if INFO = -i, the i-th argument had an illegal value

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             The matrix Q is represented as a product of elementary reflectors

                Q = H(k)**H . . . H(2)**H H(1)**H, where k = min(m,n).

             Each H(i) has the form

                H(i) = I - tau * v * v**H

             where tau is a complex scalar, and v is a complex vector with
             v(1:i-1) = 0 and v(i) = 1; conjg(v(i+1:n)) is stored on exit in
             A(i,i+1:n), and tau in TAU(i).

   subroutine zgelqf (integer M, integer N, complex*16, dimension( lda, * ) A, integer LDA,
       complex*16, dimension( * ) TAU, complex*16, dimension( * ) WORK, integer LWORK, integer
       INFO)
       ZGELQF

       Purpose:

            ZGELQF computes an LQ factorization of a complex M-by-N matrix A:

               A = ( L 0 ) *  Q

            where:

               Q is a N-by-N orthogonal matrix;
               L is a lower-triangular M-by-M matrix;
               0 is a M-by-(N-M) zero matrix, if M < N.

       Parameters
           M

                     M is INTEGER
                     The number of rows of the matrix A.  M >= 0.

           N

                     N is INTEGER
                     The number of columns of the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the M-by-N matrix A.
                     On exit, the elements on and below the diagonal of the array
                     contain the m-by-min(m,n) lower trapezoidal matrix L (L is
                     lower triangular if m <= n); the elements above the diagonal,
                     with the array TAU, represent the unitary matrix Q as a
                     product of elementary reflectors (see Further Details).

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,M).

           TAU

                     TAU is COMPLEX*16 array, dimension (min(M,N))
                     The scalar factors of the elementary reflectors (see Further
                     Details).

           WORK

                     WORK is COMPLEX*16 array, dimension (MAX(1,LWORK))
                     On exit, if INFO = 0, WORK(1) returns the optimal LWORK.

           LWORK

                     LWORK is INTEGER
                     The dimension of the array WORK.  LWORK >= max(1,M).
                     For optimum performance LWORK >= M*NB, where NB is the
                     optimal blocksize.

                     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.

           INFO

                     INFO is INTEGER
                     = 0:  successful exit
                     < 0:  if INFO = -i, the i-th argument had an illegal value

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             The matrix Q is represented as a product of elementary reflectors

                Q = H(k)**H . . . H(2)**H H(1)**H, where k = min(m,n).

             Each H(i) has the form

                H(i) = I - tau * v * v**H

             where tau is a complex scalar, and v is a complex vector with
             v(1:i-1) = 0 and v(i) = 1; conjg(v(i+1:n)) is stored on exit in
             A(i,i+1:n), and tau in TAU(i).

   subroutine zgemqrt (character SIDE, character TRANS, integer M, integer N, integer K, integer
       NB, complex*16, dimension( ldv, * ) V, integer LDV, complex*16, dimension( ldt, * ) T,
       integer LDT, complex*16, dimension( ldc, * ) C, integer LDC, complex*16, dimension( * )
       WORK, integer INFO)
       ZGEMQRT

       Purpose:

            ZGEMQRT overwrites the general complex M-by-N matrix C with

                            SIDE = 'L'     SIDE = 'R'
            TRANS = 'N':      Q C            C Q
            TRANS = 'C':    Q**H C            C Q**H

            where Q is a complex orthogonal matrix defined as the product of K
            elementary reflectors:

                  Q = H(1) H(2) . . . H(K) = I - V T V**H

            generated using the compact WY representation as returned by ZGEQRT.

            Q is of order M if SIDE = 'L' and of order N  if SIDE = 'R'.

       Parameters
           SIDE

                     SIDE is CHARACTER*1
                     = 'L': apply Q or Q**H from the Left;
                     = 'R': apply Q or Q**H from the Right.

           TRANS

                     TRANS is CHARACTER*1
                     = 'N':  No transpose, apply Q;
                     = 'C':  Conjugate transpose, apply Q**H.

           M

                     M is INTEGER
                     The number of rows of the matrix C. M >= 0.

           N

                     N is INTEGER
                     The number of columns of the matrix C. N >= 0.

           K

                     K is INTEGER
                     The number of elementary reflectors whose product defines
                     the matrix Q.
                     If SIDE = 'L', M >= K >= 0;
                     if SIDE = 'R', N >= K >= 0.

           NB

                     NB is INTEGER
                     The block size used for the storage of T.  K >= NB >= 1.
                     This must be the same value of NB used to generate T
                     in ZGEQRT.

           V

                     V is COMPLEX*16 array, dimension (LDV,K)
                     The i-th column must contain the vector which defines the
                     elementary reflector H(i), for i = 1,2,...,k, as returned by
                     ZGEQRT in the first K columns of its array argument A.

           LDV

                     LDV is INTEGER
                     The leading dimension of the array V.
                     If SIDE = 'L', LDA >= max(1,M);
                     if SIDE = 'R', LDA >= max(1,N).

           T

                     T is COMPLEX*16 array, dimension (LDT,K)
                     The upper triangular factors of the block reflectors
                     as returned by ZGEQRT, stored as a NB-by-N matrix.

           LDT

                     LDT is INTEGER
                     The leading dimension of the array T.  LDT >= NB.

           C

                     C is COMPLEX*16 array, dimension (LDC,N)
                     On entry, the M-by-N matrix C.
                     On exit, C is overwritten by Q C, Q**H C, C Q**H or C Q.

           LDC

                     LDC is INTEGER
                     The leading dimension of the array C. LDC >= max(1,M).

           WORK

                     WORK is COMPLEX*16 array. The dimension of WORK is
                      N*NB if SIDE = 'L', or  M*NB if SIDE = 'R'.

           INFO

                     INFO is INTEGER
                     = 0:  successful exit
                     < 0:  if INFO = -i, the i-th argument had an illegal value

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

   subroutine zgeql2 (integer M, integer N, complex*16, dimension( lda, * ) A, integer LDA,
       complex*16, dimension( * ) TAU, complex*16, dimension( * ) WORK, integer INFO)
       ZGEQL2 computes the QL factorization of a general rectangular matrix using an unblocked
       algorithm.

       Purpose:

            ZGEQL2 computes a QL factorization of a complex m by n matrix A:
            A = Q * L.

       Parameters
           M

                     M is INTEGER
                     The number of rows of the matrix A.  M >= 0.

           N

                     N is INTEGER
                     The number of columns of the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the m by n matrix A.
                     On exit, if m >= n, the lower triangle of the subarray
                     A(m-n+1:m,1:n) contains the n by n lower triangular matrix L;
                     if m <= n, the elements on and below the (n-m)-th
                     superdiagonal contain the m by n lower trapezoidal matrix L;
                     the remaining elements, with the array TAU, represent the
                     unitary matrix Q as a product of elementary reflectors
                     (see Further Details).

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,M).

           TAU

                     TAU is COMPLEX*16 array, dimension (min(M,N))
                     The scalar factors of the elementary reflectors (see Further
                     Details).

           WORK

                     WORK is COMPLEX*16 array, dimension (N)

           INFO

                     INFO is INTEGER
                     = 0: successful exit
                     < 0: if INFO = -i, the i-th argument had an illegal value

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             The matrix Q is represented as a product of elementary reflectors

                Q = H(k) . . . H(2) H(1), where k = min(m,n).

             Each H(i) has the form

                H(i) = I - tau * v * v**H

             where tau is a complex scalar, and v is a complex vector with
             v(m-k+i+1:m) = 0 and v(m-k+i) = 1; v(1:m-k+i-1) is stored on exit in
             A(1:m-k+i-1,n-k+i), and tau in TAU(i).

   subroutine zgeqlf (integer M, integer N, complex*16, dimension( lda, * ) A, integer LDA,
       complex*16, dimension( * ) TAU, complex*16, dimension( * ) WORK, integer LWORK, integer
       INFO)
       ZGEQLF

       Purpose:

            ZGEQLF computes a QL factorization of a complex M-by-N matrix A:
            A = Q * L.

       Parameters
           M

                     M is INTEGER
                     The number of rows of the matrix A.  M >= 0.

           N

                     N is INTEGER
                     The number of columns of the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the M-by-N matrix A.
                     On exit,
                     if m >= n, the lower triangle of the subarray
                     A(m-n+1:m,1:n) contains the N-by-N lower triangular matrix L;
                     if m <= n, the elements on and below the (n-m)-th
                     superdiagonal contain the M-by-N lower trapezoidal matrix L;
                     the remaining elements, with the array TAU, represent the
                     unitary matrix Q as a product of elementary reflectors
                     (see Further Details).

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,M).

           TAU

                     TAU is COMPLEX*16 array, dimension (min(M,N))
                     The scalar factors of the elementary reflectors (see Further
                     Details).

           WORK

                     WORK is COMPLEX*16 array, dimension (MAX(1,LWORK))
                     On exit, if INFO = 0, WORK(1) returns the optimal LWORK.

           LWORK

                     LWORK is INTEGER
                     The dimension of the array WORK.  LWORK >= max(1,N).
                     For optimum performance LWORK >= N*NB, where NB is
                     the optimal blocksize.

                     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.

           INFO

                     INFO is INTEGER
                     = 0:  successful exit
                     < 0:  if INFO = -i, the i-th argument had an illegal value

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             The matrix Q is represented as a product of elementary reflectors

                Q = H(k) . . . H(2) H(1), where k = min(m,n).

             Each H(i) has the form

                H(i) = I - tau * v * v**H

             where tau is a complex scalar, and v is a complex vector with
             v(m-k+i+1:m) = 0 and v(m-k+i) = 1; v(1:m-k+i-1) is stored on exit in
             A(1:m-k+i-1,n-k+i), and tau in TAU(i).

   subroutine zgeqp3 (integer M, integer N, complex*16, dimension( lda, * ) A, integer LDA,
       integer, dimension( * ) JPVT, complex*16, dimension( * ) TAU, complex*16, dimension( * )
       WORK, integer LWORK, double precision, dimension( * ) RWORK, integer INFO)
       ZGEQP3

       Purpose:

            ZGEQP3 computes a QR factorization with column pivoting of a
            matrix A:  A*P = Q*R  using Level 3 BLAS.

       Parameters
           M

                     M is INTEGER
                     The number of rows of the matrix A. M >= 0.

           N

                     N is INTEGER
                     The number of columns of the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the M-by-N matrix A.
                     On exit, the upper triangle of the array contains the
                     min(M,N)-by-N upper trapezoidal matrix R; the elements below
                     the diagonal, together with the array TAU, represent the
                     unitary matrix Q as a product of min(M,N) elementary
                     reflectors.

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A. LDA >= max(1,M).

           JPVT

                     JPVT is INTEGER array, dimension (N)
                     On entry, if JPVT(J).ne.0, the J-th column of A is permuted
                     to the front of A*P (a leading column); if JPVT(J)=0,
                     the J-th column of A is a free column.
                     On exit, if JPVT(J)=K, then the J-th column of A*P was the
                     the K-th column of A.

           TAU

                     TAU is COMPLEX*16 array, dimension (min(M,N))
                     The scalar factors of the elementary reflectors.

           WORK

                     WORK is COMPLEX*16 array, dimension (MAX(1,LWORK))
                     On exit, if INFO=0, WORK(1) returns the optimal LWORK.

           LWORK

                     LWORK is INTEGER
                     The dimension of the array WORK. LWORK >= N+1.
                     For optimal performance LWORK >= ( N+1 )*NB, where NB
                     is the optimal blocksize.

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

           RWORK

                     RWORK is DOUBLE PRECISION array, dimension (2*N)

           INFO

                     INFO is INTEGER
                     = 0: successful exit.
                     < 0: if INFO = -i, the i-th argument had an illegal value.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             The matrix Q is represented as a product of elementary reflectors

                Q = H(1) H(2) . . . H(k), where k = min(m,n).

             Each H(i) has the form

                H(i) = I - tau * v * v**H

             where tau is a complex scalar, and v is a real/complex vector
             with v(1:i-1) = 0 and v(i) = 1; v(i+1:m) is stored on exit in
             A(i+1:m,i), and tau in TAU(i).

       Contributors:
           G. Quintana-Orti, Depto. de Informatica, Universidad Jaime I, Spain X. Sun, Computer
           Science Dept., Duke University, USA

   subroutine zgeqr2 (integer M, integer N, complex*16, dimension( lda, * ) A, integer LDA,
       complex*16, dimension( * ) TAU, complex*16, dimension( * ) WORK, integer INFO)
       ZGEQR2 computes the QR factorization of a general rectangular matrix using an unblocked
       algorithm.

       Purpose:

            ZGEQR2 computes a QR factorization of a complex m-by-n matrix A:

               A = Q * ( R ),
                       ( 0 )

            where:

               Q is a m-by-m orthogonal matrix;
               R is an upper-triangular n-by-n matrix;
               0 is a (m-n)-by-n zero matrix, if m > n.

       Parameters
           M

                     M is INTEGER
                     The number of rows of the matrix A.  M >= 0.

           N

                     N is INTEGER
                     The number of columns of the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the m by n matrix A.
                     On exit, the elements on and above the diagonal of the array
                     contain the min(m,n) by n upper trapezoidal matrix R (R is
                     upper triangular if m >= n); the elements below the diagonal,
                     with the array TAU, represent the unitary matrix Q as a
                     product of elementary reflectors (see Further Details).

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,M).

           TAU

                     TAU is COMPLEX*16 array, dimension (min(M,N))
                     The scalar factors of the elementary reflectors (see Further
                     Details).

           WORK

                     WORK is COMPLEX*16 array, dimension (N)

           INFO

                     INFO is INTEGER
                     = 0: successful exit
                     < 0: if INFO = -i, the i-th argument had an illegal value

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             The matrix Q is represented as a product of elementary reflectors

                Q = H(1) H(2) . . . H(k), where k = min(m,n).

             Each H(i) has the form

                H(i) = I - tau * v * v**H

             where tau is a complex scalar, and v is a complex vector with
             v(1:i-1) = 0 and v(i) = 1; v(i+1:m) is stored on exit in A(i+1:m,i),
             and tau in TAU(i).

   subroutine zgeqr2p (integer M, integer N, complex*16, dimension( lda, * ) A, integer LDA,
       complex*16, dimension( * ) TAU, complex*16, dimension( * ) WORK, integer INFO)
       ZGEQR2P computes the QR factorization of a general rectangular matrix with non-negative
       diagonal elements using an unblocked algorithm.

       Purpose:

            ZGEQR2P computes a QR factorization of a complex m-by-n matrix A:

               A = Q * ( R ),
                       ( 0 )

            where:

               Q is a m-by-m orthogonal matrix;
               R is an upper-triangular n-by-n matrix with nonnegative diagonal
               entries;
               0 is a (m-n)-by-n zero matrix, if m > n.

       Parameters
           M

                     M is INTEGER
                     The number of rows of the matrix A.  M >= 0.

           N

                     N is INTEGER
                     The number of columns of the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the m by n matrix A.
                     On exit, the elements on and above the diagonal of the array
                     contain the min(m,n) by n upper trapezoidal matrix R (R is
                     upper triangular if m >= n). The diagonal entries of R
                     are real and nonnegative; the elements below the diagonal,
                     with the array TAU, represent the unitary matrix Q as a
                     product of elementary reflectors (see Further Details).

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,M).

           TAU

                     TAU is COMPLEX*16 array, dimension (min(M,N))
                     The scalar factors of the elementary reflectors (see Further
                     Details).

           WORK

                     WORK is COMPLEX*16 array, dimension (N)

           INFO

                     INFO is INTEGER
                     = 0: successful exit
                     < 0: if INFO = -i, the i-th argument had an illegal value

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             The matrix Q is represented as a product of elementary reflectors

                Q = H(1) H(2) . . . H(k), where k = min(m,n).

             Each H(i) has the form

                H(i) = I - tau * v * v**H

             where tau is a complex scalar, and v is a complex vector with
             v(1:i-1) = 0 and v(i) = 1; v(i+1:m) is stored on exit in A(i+1:m,i),
             and tau in TAU(i).

            See Lapack Working Note 203 for details

   subroutine zgeqrf (integer M, integer N, complex*16, dimension( lda, * ) A, integer LDA,
       complex*16, dimension( * ) TAU, complex*16, dimension( * ) WORK, integer LWORK, integer
       INFO)
       ZGEQRF

       Purpose:

            ZGEQRF computes a QR factorization of a complex M-by-N matrix A:

               A = Q * ( R ),
                       ( 0 )

            where:

               Q is a M-by-M orthogonal matrix;
               R is an upper-triangular N-by-N matrix;
               0 is a (M-N)-by-N zero matrix, if M > N.

       Parameters
           M

                     M is INTEGER
                     The number of rows of the matrix A.  M >= 0.

           N

                     N is INTEGER
                     The number of columns of the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the M-by-N matrix A.
                     On exit, the elements on and above the diagonal of the array
                     contain the min(M,N)-by-N upper trapezoidal matrix R (R is
                     upper triangular if m >= n); the elements below the diagonal,
                     with the array TAU, represent the unitary matrix Q as a
                     product of min(m,n) elementary reflectors (see Further
                     Details).

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,M).

           TAU

                     TAU is COMPLEX*16 array, dimension (min(M,N))
                     The scalar factors of the elementary reflectors (see Further
                     Details).

           WORK

                     WORK is COMPLEX*16 array, dimension (MAX(1,LWORK))
                     On exit, if INFO = 0, WORK(1) returns the optimal LWORK.

           LWORK

                     LWORK is INTEGER
                     The dimension of the array WORK.
                     LWORK >= 1, if MIN(M,N) = 0, and LWORK >= N, otherwise.
                     For optimum performance LWORK >= N*NB, where NB is
                     the optimal blocksize.

                     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.

           INFO

                     INFO is INTEGER
                     = 0:  successful exit
                     < 0:  if INFO = -i, the i-th argument had an illegal value

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             The matrix Q is represented as a product of elementary reflectors

                Q = H(1) H(2) . . . H(k), where k = min(m,n).

             Each H(i) has the form

                H(i) = I - tau * v * v**H

             where tau is a complex scalar, and v is a complex vector with
             v(1:i-1) = 0 and v(i) = 1; v(i+1:m) is stored on exit in A(i+1:m,i),
             and tau in TAU(i).

   subroutine zgeqrfp (integer M, integer N, complex*16, dimension( lda, * ) A, integer LDA,
       complex*16, dimension( * ) TAU, complex*16, dimension( * ) WORK, integer LWORK, integer
       INFO)
       ZGEQRFP

       Purpose:

            ZGEQR2P computes a QR factorization of a complex M-by-N matrix A:

               A = Q * ( R ),
                       ( 0 )

            where:

               Q is a M-by-M orthogonal matrix;
               R is an upper-triangular N-by-N matrix with nonnegative diagonal
               entries;
               0 is a (M-N)-by-N zero matrix, if M > N.

       Parameters
           M

                     M is INTEGER
                     The number of rows of the matrix A.  M >= 0.

           N

                     N is INTEGER
                     The number of columns of the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the M-by-N matrix A.
                     On exit, the elements on and above the diagonal of the array
                     contain the min(M,N)-by-N upper trapezoidal matrix R (R is
                     upper triangular if m >= n). The diagonal entries of R
                     are real and nonnegative; The elements below the diagonal,
                     with the array TAU, represent the unitary matrix Q as a
                     product of min(m,n) elementary reflectors (see Further
                     Details).

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,M).

           TAU

                     TAU is COMPLEX*16 array, dimension (min(M,N))
                     The scalar factors of the elementary reflectors (see Further
                     Details).

           WORK

                     WORK is COMPLEX*16 array, dimension (MAX(1,LWORK))
                     On exit, if INFO = 0, WORK(1) returns the optimal LWORK.

           LWORK

                     LWORK is INTEGER
                     The dimension of the array WORK.  LWORK >= max(1,N).
                     For optimum performance LWORK >= N*NB, where NB is
                     the optimal blocksize.

                     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.

           INFO

                     INFO is INTEGER
                     = 0:  successful exit
                     < 0:  if INFO = -i, the i-th argument had an illegal value

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             The matrix Q is represented as a product of elementary reflectors

                Q = H(1) H(2) . . . H(k), where k = min(m,n).

             Each H(i) has the form

                H(i) = I - tau * v * v**H

             where tau is a complex scalar, and v is a complex vector with
             v(1:i-1) = 0 and v(i) = 1; v(i+1:m) is stored on exit in A(i+1:m,i),
             and tau in TAU(i).

            See Lapack Working Note 203 for details

   subroutine zgeqrt (integer M, integer N, integer NB, complex*16, dimension( lda, * ) A,
       integer LDA, complex*16, dimension( ldt, * ) T, integer LDT, complex*16, dimension( * )
       WORK, integer INFO)
       ZGEQRT

       Purpose:

            ZGEQRT computes a blocked QR factorization of a complex M-by-N matrix A
            using the compact WY representation of Q.

       Parameters
           M

                     M is INTEGER
                     The number of rows of the matrix A.  M >= 0.

           N

                     N is INTEGER
                     The number of columns of the matrix A.  N >= 0.

           NB

                     NB is INTEGER
                     The block size to be used in the blocked QR.  MIN(M,N) >= NB >= 1.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the M-by-N matrix A.
                     On exit, the elements on and above the diagonal of the array
                     contain the min(M,N)-by-N upper trapezoidal matrix R (R is
                     upper triangular if M >= N); the elements below the diagonal
                     are the columns of V.

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,M).

           T

                     T is COMPLEX*16 array, dimension (LDT,MIN(M,N))
                     The upper triangular block reflectors stored in compact form
                     as a sequence of upper triangular blocks.  See below
                     for further details.

           LDT

                     LDT is INTEGER
                     The leading dimension of the array T.  LDT >= NB.

           WORK

                     WORK is COMPLEX*16 array, dimension (NB*N)

           INFO

                     INFO is INTEGER
                     = 0:  successful exit
                     < 0:  if INFO = -i, the i-th argument had an illegal value

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             The matrix V stores the elementary reflectors H(i) in the i-th column
             below the diagonal. For example, if M=5 and N=3, the matrix V is

                          V = (  1       )
                              ( v1  1    )
                              ( v1 v2  1 )
                              ( v1 v2 v3 )
                              ( v1 v2 v3 )

             where the vi's represent the vectors which define H(i), which are returned
             in the matrix A.  The 1's along the diagonal of V are not stored in A.

             Let K=MIN(M,N).  The number of blocks is B = ceiling(K/NB), where each
             block is of order NB except for the last block, which is of order
             IB = K - (B-1)*NB.  For each of the B blocks, a upper triangular block
             reflector factor is computed: T1, T2, ..., TB.  The NB-by-NB (and IB-by-IB
             for the last block) T's are stored in the NB-by-K matrix T as

                          T = (T1 T2 ... TB).

   subroutine zgeqrt2 (integer M, integer N, complex*16, dimension( lda, * ) A, integer LDA,
       complex*16, dimension( ldt, * ) T, integer LDT, integer INFO)
       ZGEQRT2 computes a QR factorization of a general real or complex matrix using the compact
       WY representation of Q.

       Purpose:

            ZGEQRT2 computes a QR factorization of a complex M-by-N matrix A,
            using the compact WY representation of Q.

       Parameters
           M

                     M is INTEGER
                     The number of rows of the matrix A.  M >= N.

           N

                     N is INTEGER
                     The number of columns of the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the complex M-by-N matrix A.  On exit, the elements on and
                     above the diagonal contain the N-by-N upper triangular matrix R; the
                     elements below the diagonal are the columns of V.  See below for
                     further details.

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,M).

           T

                     T is COMPLEX*16 array, dimension (LDT,N)
                     The N-by-N upper triangular factor of the block reflector.
                     The elements on and above the diagonal contain the block
                     reflector T; the elements below the diagonal are not used.
                     See below for further details.

           LDT

                     LDT is INTEGER
                     The leading dimension of the array T.  LDT >= max(1,N).

           INFO

                     INFO is INTEGER
                     = 0: successful exit
                     < 0: if INFO = -i, the i-th argument had an illegal value

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             The matrix V stores the elementary reflectors H(i) in the i-th column
             below the diagonal. For example, if M=5 and N=3, the matrix V is

                          V = (  1       )
                              ( v1  1    )
                              ( v1 v2  1 )
                              ( v1 v2 v3 )
                              ( v1 v2 v3 )

             where the vi's represent the vectors which define H(i), which are returned
             in the matrix A.  The 1's along the diagonal of V are not stored in A.  The
             block reflector H is then given by

                          H = I - V * T * V**H

             where V**H is the conjugate transpose of V.

   recursive subroutine zgeqrt3 (integer M, integer N, complex*16, dimension( lda, * ) A, integer
       LDA, complex*16, dimension( ldt, * ) T, integer LDT, integer INFO)
       ZGEQRT3 recursively computes a QR factorization of a general real or complex matrix using
       the compact WY representation of Q.

       Purpose:

            ZGEQRT3 recursively computes a QR factorization of a complex M-by-N
            matrix A, using the compact WY representation of Q.

            Based on the algorithm of Elmroth and Gustavson,
            IBM J. Res. Develop. Vol 44 No. 4 July 2000.

       Parameters
           M

                     M is INTEGER
                     The number of rows of the matrix A.  M >= N.

           N

                     N is INTEGER
                     The number of columns of the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the complex M-by-N matrix A.  On exit, the elements on
                     and above the diagonal contain the N-by-N upper triangular matrix R;
                     the elements below the diagonal are the columns of V.  See below for
                     further details.

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,M).

           T

                     T is COMPLEX*16 array, dimension (LDT,N)
                     The N-by-N upper triangular factor of the block reflector.
                     The elements on and above the diagonal contain the block
                     reflector T; the elements below the diagonal are not used.
                     See below for further details.

           LDT

                     LDT is INTEGER
                     The leading dimension of the array T.  LDT >= max(1,N).

           INFO

                     INFO is INTEGER
                     = 0: successful exit
                     < 0: if INFO = -i, the i-th argument had an illegal value

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             The matrix V stores the elementary reflectors H(i) in the i-th column
             below the diagonal. For example, if M=5 and N=3, the matrix V is

                          V = (  1       )
                              ( v1  1    )
                              ( v1 v2  1 )
                              ( v1 v2 v3 )
                              ( v1 v2 v3 )

             where the vi's represent the vectors which define H(i), which are returned
             in the matrix A.  The 1's along the diagonal of V are not stored in A.  The
             block reflector H is then given by

                          H = I - V * T * V**H

             where V**H is the conjugate transpose of V.

             For details of the algorithm, see Elmroth and Gustavson (cited above).

   subroutine zgerfs (character TRANS, integer N, integer NRHS, complex*16, dimension( lda, * )
       A, integer LDA, complex*16, dimension( ldaf, * ) AF, integer LDAF, integer, dimension( * )
       IPIV, complex*16, dimension( ldb, * ) B, integer LDB, complex*16, dimension( ldx, * ) X,
       integer LDX, double precision, dimension( * ) FERR, double precision, dimension( * ) BERR,
       complex*16, dimension( * ) WORK, double precision, dimension( * ) RWORK, integer INFO)
       ZGERFS

       Purpose:

            ZGERFS improves the computed solution to a system of linear
            equations and provides error bounds and backward error estimates for
            the solution.

       Parameters
           TRANS

                     TRANS is CHARACTER*1
                     Specifies the form of the system of equations:
                     = 'N':  A * X = B     (No transpose)
                     = 'T':  A**T * X = B  (Transpose)
                     = 'C':  A**H * X = B  (Conjugate transpose)

           N

                     N is INTEGER
                     The order of the matrix A.  N >= 0.

           NRHS

                     NRHS is INTEGER
                     The number of right hand sides, i.e., the number of columns
                     of the matrices B and X.  NRHS >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     The original N-by-N matrix A.

           LDA

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

           AF

                     AF is COMPLEX*16 array, dimension (LDAF,N)
                     The factors L and U from the factorization A = P*L*U
                     as computed by ZGETRF.

           LDAF

                     LDAF is INTEGER
                     The leading dimension of the array AF.  LDAF >= max(1,N).

           IPIV

                     IPIV is INTEGER array, dimension (N)
                     The pivot indices from ZGETRF; for 1<=i<=N, row i of the
                     matrix was interchanged with row IPIV(i).

           B

                     B is COMPLEX*16 array, dimension (LDB,NRHS)
                     The right hand side matrix B.

           LDB

                     LDB is INTEGER
                     The leading dimension of the array B.  LDB >= max(1,N).

           X

                     X is COMPLEX*16 array, dimension (LDX,NRHS)
                     On entry, the solution matrix X, as computed by ZGETRS.
                     On exit, the improved solution matrix X.

           LDX

                     LDX is INTEGER
                     The leading dimension of the array X.  LDX >= max(1,N).

           FERR

                     FERR is DOUBLE PRECISION array, dimension (NRHS)
                     The estimated forward error bound for each solution vector
                     X(j) (the j-th column of the solution matrix X).
                     If XTRUE is the true solution corresponding to X(j), FERR(j)
                     is an estimated upper bound for the magnitude of the largest
                     element in (X(j) - XTRUE) divided by the magnitude of the
                     largest element in X(j).  The estimate is as reliable as
                     the estimate for RCOND, and is almost always a slight
                     overestimate of the true error.

           BERR

                     BERR is DOUBLE PRECISION array, dimension (NRHS)
                     The componentwise relative backward error of each solution
                     vector X(j) (i.e., the smallest relative change in
                     any element of A or B that makes X(j) an exact solution).

           WORK

                     WORK is COMPLEX*16 array, dimension (2*N)

           RWORK

                     RWORK is DOUBLE PRECISION array, dimension (N)

           INFO

                     INFO is INTEGER
                     = 0:  successful exit
                     < 0:  if INFO = -i, the i-th argument had an illegal value

       Internal Parameters:

             ITMAX is the maximum number of steps of iterative refinement.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

   subroutine zgerfsx (character TRANS, character EQUED, integer N, integer NRHS, complex*16,
       dimension( lda, * ) A, integer LDA, complex*16, dimension( ldaf, * ) AF, integer LDAF,
       integer, dimension( * ) IPIV, double precision, dimension( * ) R, double precision,
       dimension( * ) C, complex*16, dimension( ldb, * ) B, integer LDB, complex*16, dimension(
       ldx , * ) X, integer LDX, double precision RCOND, double precision, dimension( * ) BERR,
       integer N_ERR_BNDS, double precision, dimension( nrhs, * ) ERR_BNDS_NORM, double
       precision, dimension( nrhs, * ) ERR_BNDS_COMP, integer NPARAMS, double precision,
       dimension( * ) PARAMS, complex*16, dimension( * ) WORK, double precision, dimension( * )
       RWORK, integer INFO)
       ZGERFSX

       Purpose:

               ZGERFSX improves the computed solution to a system of linear
               equations and provides error bounds and backward error estimates
               for the solution.  In addition to normwise error bound, the code
               provides maximum componentwise error bound if possible.  See
               comments for ERR_BNDS_NORM and ERR_BNDS_COMP for details of the
               error bounds.

               The original system of linear equations may have been equilibrated
               before calling this routine, as described by arguments EQUED, R
               and C below. In this case, the solution and error bounds returned
               are for the original unequilibrated system.

                Some optional parameters are bundled in the PARAMS array.  These
                settings determine how refinement is performed, but often the
                defaults are acceptable.  If the defaults are acceptable, users
                can pass NPARAMS = 0 which prevents the source code from accessing
                the PARAMS argument.

       Parameters
           TRANS

                     TRANS is CHARACTER*1
                Specifies the form of the system of equations:
                  = 'N':  A * X = B     (No transpose)
                  = 'T':  A**T * X = B  (Transpose)
                  = 'C':  A**H * X = B  (Conjugate transpose)

           EQUED

                     EQUED is CHARACTER*1
                Specifies the form of equilibration that was done to A
                before calling this routine. This is needed to compute
                the solution and error bounds correctly.
                  = 'N':  No equilibration
                  = 'R':  Row equilibration, i.e., A has been premultiplied by
                          diag(R).
                  = 'C':  Column equilibration, i.e., A has been postmultiplied
                          by diag(C).
                  = 'B':  Both row and column equilibration, i.e., A has been
                          replaced by diag(R) * A * diag(C).
                          The right hand side B has been changed accordingly.

           N

                     N is INTEGER
                The order of the matrix A.  N >= 0.

           NRHS

                     NRHS is INTEGER
                The number of right hand sides, i.e., the number of columns
                of the matrices B and X.  NRHS >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                The original N-by-N matrix A.

           LDA

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

           AF

                     AF is COMPLEX*16 array, dimension (LDAF,N)
                The factors L and U from the factorization A = P*L*U
                as computed by ZGETRF.

           LDAF

                     LDAF is INTEGER
                The leading dimension of the array AF.  LDAF >= max(1,N).

           IPIV

                     IPIV is INTEGER array, dimension (N)
                The pivot indices from ZGETRF; for 1<=i<=N, row i of the
                matrix was interchanged with row IPIV(i).

           R

                     R is DOUBLE PRECISION array, dimension (N)
                The row scale factors for A.  If EQUED = 'R' or 'B', A is
                multiplied on the left by diag(R); if EQUED = 'N' or 'C', R
                is not accessed.
                If R is accessed, each element of R should be a power of the radix
                to ensure a reliable solution and error estimates. Scaling by
                powers of the radix does not cause rounding errors unless the
                result underflows or overflows. Rounding errors during scaling
                lead to refining with a matrix that is not equivalent to the
                input matrix, producing error estimates that may not be
                reliable.

           C

                     C is DOUBLE PRECISION array, dimension (N)
                The column scale factors for A.  If EQUED = 'C' or 'B', A is
                multiplied on the right by diag(C); if EQUED = 'N' or 'R', C
                is not accessed.
                If C is accessed, each element of C should be a power of the radix
                to ensure a reliable solution and error estimates. Scaling by
                powers of the radix does not cause rounding errors unless the
                result underflows or overflows. Rounding errors during scaling
                lead to refining with a matrix that is not equivalent to the
                input matrix, producing error estimates that may not be
                reliable.

           B

                     B is COMPLEX*16 array, dimension (LDB,NRHS)
                The right hand side matrix B.

           LDB

                     LDB is INTEGER
                The leading dimension of the array B.  LDB >= max(1,N).

           X

                     X is COMPLEX*16 array, dimension (LDX,NRHS)
                On entry, the solution matrix X, as computed by ZGETRS.
                On exit, the improved solution matrix X.

           LDX

                     LDX is INTEGER
                The leading dimension of the array X.  LDX >= max(1,N).

           RCOND

                     RCOND is DOUBLE PRECISION
                Reciprocal scaled condition number.  This is an estimate of the
                reciprocal Skeel condition number of the matrix A after
                equilibration (if done).  If this is less than the machine
                precision (in particular, if it is zero), the matrix is singular
                to working precision.  Note that the error may still be small even
                if this number is very small and the matrix appears ill-
                conditioned.

           BERR

                     BERR is DOUBLE PRECISION array, dimension (NRHS)
                Componentwise relative backward error.  This is the
                componentwise relative backward error of each solution vector X(j)
                (i.e., the smallest relative change in any element of A or B that
                makes X(j) an exact solution).

           N_ERR_BNDS

                     N_ERR_BNDS is INTEGER
                Number of error bounds to return for each right hand side
                and each type (normwise or componentwise).  See ERR_BNDS_NORM and
                ERR_BNDS_COMP below.

           ERR_BNDS_NORM

                     ERR_BNDS_NORM is DOUBLE PRECISION array, dimension (NRHS, N_ERR_BNDS)
                For each right-hand side, this array contains information about
                various error bounds and condition numbers corresponding to the
                normwise relative error, which is defined as follows:

                Normwise relative error in the ith solution vector:
                        max_j (abs(XTRUE(j,i) - X(j,i)))
                       ------------------------------
                             max_j abs(X(j,i))

                The array is indexed by the type of error information as described
                below. There currently are up to three pieces of information
                returned.

                The first index in ERR_BNDS_NORM(i,:) corresponds to the ith
                right-hand side.

                The second index in ERR_BNDS_NORM(:,err) contains the following
                three fields:
                err = 1 'Trust/don't trust' boolean. Trust the answer if the
                         reciprocal condition number is less than the threshold
                         sqrt(n) * dlamch('Epsilon').

                err = 2 'Guaranteed' error bound: The estimated forward error,
                         almost certainly within a factor of 10 of the true error
                         so long as the next entry is greater than the threshold
                         sqrt(n) * dlamch('Epsilon'). This error bound should only
                         be trusted if the previous boolean is true.

                err = 3  Reciprocal condition number: Estimated normwise
                         reciprocal condition number.  Compared with the threshold
                         sqrt(n) * dlamch('Epsilon') to determine if the error
                         estimate is 'guaranteed'. These reciprocal condition
                         numbers are 1 / (norm(Z^{-1},inf) * norm(Z,inf)) for some
                         appropriately scaled matrix Z.
                         Let Z = S*A, where S scales each row by a power of the
                         radix so all absolute row sums of Z are approximately 1.

                See Lapack Working Note 165 for further details and extra
                cautions.

           ERR_BNDS_COMP

                     ERR_BNDS_COMP is DOUBLE PRECISION array, dimension (NRHS, N_ERR_BNDS)
                For each right-hand side, this array contains information about
                various error bounds and condition numbers corresponding to the
                componentwise relative error, which is defined as follows:

                Componentwise relative error in the ith solution vector:
                               abs(XTRUE(j,i) - X(j,i))
                        max_j ----------------------
                                    abs(X(j,i))

                The array is indexed by the right-hand side i (on which the
                componentwise relative error depends), and the type of error
                information as described below. There currently are up to three
                pieces of information returned for each right-hand side. If
                componentwise accuracy is not requested (PARAMS(3) = 0.0), then
                ERR_BNDS_COMP is not accessed.  If N_ERR_BNDS < 3, then at most
                the first (:,N_ERR_BNDS) entries are returned.

                The first index in ERR_BNDS_COMP(i,:) corresponds to the ith
                right-hand side.

                The second index in ERR_BNDS_COMP(:,err) contains the following
                three fields:
                err = 1 'Trust/don't trust' boolean. Trust the answer if the
                         reciprocal condition number is less than the threshold
                         sqrt(n) * dlamch('Epsilon').

                err = 2 'Guaranteed' error bound: The estimated forward error,
                         almost certainly within a factor of 10 of the true error
                         so long as the next entry is greater than the threshold
                         sqrt(n) * dlamch('Epsilon'). This error bound should only
                         be trusted if the previous boolean is true.

                err = 3  Reciprocal condition number: Estimated componentwise
                         reciprocal condition number.  Compared with the threshold
                         sqrt(n) * dlamch('Epsilon') to determine if the error
                         estimate is 'guaranteed'. These reciprocal condition
                         numbers are 1 / (norm(Z^{-1},inf) * norm(Z,inf)) for some
                         appropriately scaled matrix Z.
                         Let Z = S*(A*diag(x)), where x is the solution for the
                         current right-hand side and S scales each row of
                         A*diag(x) by a power of the radix so all absolute row
                         sums of Z are approximately 1.

                See Lapack Working Note 165 for further details and extra
                cautions.

           NPARAMS

                     NPARAMS is INTEGER
                Specifies the number of parameters set in PARAMS.  If <= 0, the
                PARAMS array is never referenced and default values are used.

           PARAMS

                     PARAMS is DOUBLE PRECISION array, dimension NPARAMS
                Specifies algorithm parameters.  If an entry is < 0.0, then
                that entry will be filled with default value used for that
                parameter.  Only positions up to NPARAMS are accessed; defaults
                are used for higher-numbered parameters.

                  PARAMS(LA_LINRX_ITREF_I = 1) : Whether to perform iterative
                       refinement or not.
                    Default: 1.0D+0
                       = 0.0:  No refinement is performed, and no error bounds are
                               computed.
                       = 1.0:  Use the double-precision refinement algorithm,
                               possibly with doubled-single computations if the
                               compilation environment does not support DOUBLE
                               PRECISION.
                         (other values are reserved for future use)

                  PARAMS(LA_LINRX_ITHRESH_I = 2) : Maximum number of residual
                       computations allowed for refinement.
                    Default: 10
                    Aggressive: Set to 100 to permit convergence using approximate
                                factorizations or factorizations other than LU. If
                                the factorization uses a technique other than
                                Gaussian elimination, the guarantees in
                                err_bnds_norm and err_bnds_comp may no longer be
                                trustworthy.

                  PARAMS(LA_LINRX_CWISE_I = 3) : Flag determining if the code
                       will attempt to find a solution with small componentwise
                       relative error in the double-precision algorithm.  Positive
                       is true, 0.0 is false.
                    Default: 1.0 (attempt componentwise convergence)

           WORK

                     WORK is COMPLEX*16 array, dimension (2*N)

           RWORK

                     RWORK is DOUBLE PRECISION array, dimension (2*N)

           INFO

                     INFO is INTEGER
                  = 0:  Successful exit. The solution to every right-hand side is
                    guaranteed.
                  < 0:  If INFO = -i, the i-th argument had an illegal value
                  > 0 and <= N:  U(INFO,INFO) is exactly zero.  The factorization
                    has been completed, but the factor U is exactly singular, so
                    the solution and error bounds could not be computed. RCOND = 0
                    is returned.
                  = N+J: The solution corresponding to the Jth right-hand side is
                    not guaranteed. The solutions corresponding to other right-
                    hand sides K with K > J may not be guaranteed as well, but
                    only the first such right-hand side is reported. If a small
                    componentwise error is not requested (PARAMS(3) = 0.0) then
                    the Jth right-hand side is the first with a normwise error
                    bound that is not guaranteed (the smallest J such
                    that ERR_BNDS_NORM(J,1) = 0.0). By default (PARAMS(3) = 1.0)
                    the Jth right-hand side is the first with either a normwise or
                    componentwise error bound that is not guaranteed (the smallest
                    J such that either ERR_BNDS_NORM(J,1) = 0.0 or
                    ERR_BNDS_COMP(J,1) = 0.0). See the definition of
                    ERR_BNDS_NORM(:,1) and ERR_BNDS_COMP(:,1). To get information
                    about all of the right-hand sides check ERR_BNDS_NORM or
                    ERR_BNDS_COMP.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

   subroutine zgerq2 (integer M, integer N, complex*16, dimension( lda, * ) A, integer LDA,
       complex*16, dimension( * ) TAU, complex*16, dimension( * ) WORK, integer INFO)
       ZGERQ2 computes the RQ factorization of a general rectangular matrix using an unblocked
       algorithm.

       Purpose:

            ZGERQ2 computes an RQ factorization of a complex m by n matrix A:
            A = R * Q.

       Parameters
           M

                     M is INTEGER
                     The number of rows of the matrix A.  M >= 0.

           N

                     N is INTEGER
                     The number of columns of the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the m by n matrix A.
                     On exit, if m <= n, the upper triangle of the subarray
                     A(1:m,n-m+1:n) contains the m by m upper triangular matrix R;
                     if m >= n, the elements on and above the (m-n)-th subdiagonal
                     contain the m by n upper trapezoidal matrix R; the remaining
                     elements, with the array TAU, represent the unitary matrix
                     Q as a product of elementary reflectors (see Further
                     Details).

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,M).

           TAU

                     TAU is COMPLEX*16 array, dimension (min(M,N))
                     The scalar factors of the elementary reflectors (see Further
                     Details).

           WORK

                     WORK is COMPLEX*16 array, dimension (M)

           INFO

                     INFO is INTEGER
                     = 0: successful exit
                     < 0: if INFO = -i, the i-th argument had an illegal value

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             The matrix Q is represented as a product of elementary reflectors

                Q = H(1)**H H(2)**H . . . H(k)**H, where k = min(m,n).

             Each H(i) has the form

                H(i) = I - tau * v * v**H

             where tau is a complex scalar, and v is a complex vector with
             v(n-k+i+1:n) = 0 and v(n-k+i) = 1; conjg(v(1:n-k+i-1)) is stored on
             exit in A(m-k+i,1:n-k+i-1), and tau in TAU(i).

   subroutine zgerqf (integer M, integer N, complex*16, dimension( lda, * ) A, integer LDA,
       complex*16, dimension( * ) TAU, complex*16, dimension( * ) WORK, integer LWORK, integer
       INFO)
       ZGERQF

       Purpose:

            ZGERQF computes an RQ factorization of a complex M-by-N matrix A:
            A = R * Q.

       Parameters
           M

                     M is INTEGER
                     The number of rows of the matrix A.  M >= 0.

           N

                     N is INTEGER
                     The number of columns of the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the M-by-N matrix A.
                     On exit,
                     if m <= n, the upper triangle of the subarray
                     A(1:m,n-m+1:n) contains the M-by-M upper triangular matrix R;
                     if m >= n, the elements on and above the (m-n)-th subdiagonal
                     contain the M-by-N upper trapezoidal matrix R;
                     the remaining elements, with the array TAU, represent the
                     unitary matrix Q as a product of min(m,n) elementary
                     reflectors (see Further Details).

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,M).

           TAU

                     TAU is COMPLEX*16 array, dimension (min(M,N))
                     The scalar factors of the elementary reflectors (see Further
                     Details).

           WORK

                     WORK is COMPLEX*16 array, dimension (MAX(1,LWORK))
                     On exit, if INFO = 0, WORK(1) returns the optimal LWORK.

           LWORK

                     LWORK is INTEGER
                     The dimension of the array WORK.
                     LWORK >= 1, if MIN(M,N) = 0, and LWORK >= M, otherwise.
                     For optimum performance LWORK >= M*NB, where NB is
                     the optimal blocksize.

                     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.

           INFO

                     INFO is INTEGER
                     = 0:  successful exit
                     < 0:  if INFO = -i, the i-th argument had an illegal value

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             The matrix Q is represented as a product of elementary reflectors

                Q = H(1)**H H(2)**H . . . H(k)**H, where k = min(m,n).

             Each H(i) has the form

                H(i) = I - tau * v * v**H

             where tau is a complex scalar, and v is a complex vector with
             v(n-k+i+1:n) = 0 and v(n-k+i) = 1; conjg(v(1:n-k+i-1)) is stored on
             exit in A(m-k+i,1:n-k+i-1), and tau in TAU(i).

   subroutine zgesvj (character*1 JOBA, character*1 JOBU, character*1 JOBV, integer M, integer N,
       complex*16, dimension( lda, * ) A, integer LDA, double precision, dimension( n ) SVA,
       integer MV, complex*16, dimension( ldv, * ) V, integer LDV, complex*16, dimension( lwork )
       CWORK, integer LWORK, double precision, dimension( lrwork ) RWORK, integer LRWORK, integer
       INFO)
        ZGESVJ

       Purpose:

            ZGESVJ computes the singular value decomposition (SVD) of a complex
            M-by-N matrix A, where M >= N. The SVD of A is written as
                                               [++]   [xx]   [x0]   [xx]
                         A = U * SIGMA * V^*,  [++] = [xx] * [ox] * [xx]
                                               [++]   [xx]
            where SIGMA is an N-by-N diagonal matrix, U is an M-by-N orthonormal
            matrix, and V is an N-by-N unitary matrix. The diagonal elements
            of SIGMA are the singular values of A. The columns of U and V are the
            left and the right singular vectors of A, respectively.

       Parameters
           JOBA

                     JOBA is CHARACTER*1
                     Specifies the structure of A.
                     = 'L': The input matrix A is lower triangular;
                     = 'U': The input matrix A is upper triangular;
                     = 'G': The input matrix A is general M-by-N matrix, M >= N.

           JOBU

                     JOBU is CHARACTER*1
                     Specifies whether to compute the left singular vectors
                     (columns of U):
                     = 'U' or 'F': The left singular vectors corresponding to the nonzero
                            singular values are computed and returned in the leading
                            columns of A. See more details in the description of A.
                            The default numerical orthogonality threshold is set to
                            approximately TOL=CTOL*EPS, CTOL=SQRT(M), EPS=DLAMCH('E').
                     = 'C': Analogous to JOBU='U', except that user can control the
                            level of numerical orthogonality of the computed left
                            singular vectors. TOL can be set to TOL = CTOL*EPS, where
                            CTOL is given on input in the array WORK.
                            No CTOL smaller than ONE is allowed. CTOL greater
                            than 1 / EPS is meaningless. The option 'C'
                            can be used if M*EPS is satisfactory orthogonality
                            of the computed left singular vectors, so CTOL=M could
                            save few sweeps of Jacobi rotations.
                            See the descriptions of A and WORK(1).
                     = 'N': The matrix U is not computed. However, see the
                            description of A.

           JOBV

                     JOBV is CHARACTER*1
                     Specifies whether to compute the right singular vectors, that
                     is, the matrix V:
                     = 'V' or 'J': the matrix V is computed and returned in the array V
                     = 'A':  the Jacobi rotations are applied to the MV-by-N
                             array V. In other words, the right singular vector
                             matrix V is not computed explicitly; instead it is
                             applied to an MV-by-N matrix initially stored in the
                             first MV rows of V.
                     = 'N':  the matrix V is not computed and the array V is not
                             referenced

           M

                     M is INTEGER
                     The number of rows of the input matrix A. 1/DLAMCH('E') > M >= 0.

           N

                     N is INTEGER
                     The number of columns of the input matrix A.
                     M >= N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the M-by-N matrix A.
                     On exit,
                     If JOBU = 'U' .OR. JOBU = 'C':
                            If INFO = 0 :
                            RANKA orthonormal columns of U are returned in the
                            leading RANKA columns of the array A. Here RANKA <= N
                            is the number of computed singular values of A that are
                            above the underflow threshold DLAMCH('S'). The singular
                            vectors corresponding to underflowed or zero singular
                            values are not computed. The value of RANKA is returned
                            in the array RWORK as RANKA=NINT(RWORK(2)). Also see the
                            descriptions of SVA and RWORK. The computed columns of U
                            are mutually numerically orthogonal up to approximately
                            TOL=SQRT(M)*EPS (default); or TOL=CTOL*EPS (JOBU = 'C'),
                            see the description of JOBU.
                            If INFO > 0,
                            the procedure ZGESVJ did not converge in the given number
                            of iterations (sweeps). In that case, the computed
                            columns of U may not be orthogonal up to TOL. The output
                            U (stored in A), SIGMA (given by the computed singular
                            values in SVA(1:N)) and V is still a decomposition of the
                            input matrix A in the sense that the residual
                            || A - SCALE * U * SIGMA * V^* ||_2 / ||A||_2 is small.
                     If JOBU = 'N':
                            If INFO = 0 :
                            Note that the left singular vectors are 'for free' in the
                            one-sided Jacobi SVD algorithm. However, if only the
                            singular values are needed, the level of numerical
                            orthogonality of U is not an issue and iterations are
                            stopped when the columns of the iterated matrix are
                            numerically orthogonal up to approximately M*EPS. Thus,
                            on exit, A contains the columns of U scaled with the
                            corresponding singular values.
                            If INFO > 0:
                            the procedure ZGESVJ did not converge in the given number
                            of iterations (sweeps).

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,M).

           SVA

                     SVA is DOUBLE PRECISION array, dimension (N)
                     On exit,
                     If INFO = 0 :
                     depending on the value SCALE = RWORK(1), we have:
                            If SCALE = ONE:
                            SVA(1:N) contains the computed singular values of A.
                            During the computation SVA contains the Euclidean column
                            norms of the iterated matrices in the array A.
                            If SCALE .NE. ONE:
                            The singular values of A are SCALE*SVA(1:N), and this
                            factored representation is due to the fact that some of the
                            singular values of A might underflow or overflow.

                     If INFO > 0:
                     the procedure ZGESVJ did not converge in the given number of
                     iterations (sweeps) and SCALE*SVA(1:N) may not be accurate.

           MV

                     MV is INTEGER
                     If JOBV = 'A', then the product of Jacobi rotations in ZGESVJ
                     is applied to the first MV rows of V. See the description of JOBV.

           V

                     V is COMPLEX*16 array, dimension (LDV,N)
                     If JOBV = 'V', then V contains on exit the N-by-N matrix of
                                    the right singular vectors;
                     If JOBV = 'A', then V contains the product of the computed right
                                    singular vector matrix and the initial matrix in
                                    the array V.
                     If JOBV = 'N', then V is not referenced.

           LDV

                     LDV is INTEGER
                     The leading dimension of the array V, LDV >= 1.
                     If JOBV = 'V', then LDV >= max(1,N).
                     If JOBV = 'A', then LDV >= max(1,MV) .

           CWORK

                     CWORK is COMPLEX*16 array, dimension (max(1,LWORK))
                     Used as workspace.
                     If on entry LWORK = -1, then a workspace query is assumed and
                     no computation is done; CWORK(1) is set to the minial (and optimal)
                     length of CWORK.

           LWORK

                     LWORK is INTEGER.
                     Length of CWORK, LWORK >= M+N.

           RWORK

                     RWORK is DOUBLE PRECISION array, dimension (max(6,LRWORK))
                     On entry,
                     If JOBU = 'C' :
                     RWORK(1) = CTOL, where CTOL defines the threshold for convergence.
                               The process stops if all columns of A are mutually
                               orthogonal up to CTOL*EPS, EPS=DLAMCH('E').
                               It is required that CTOL >= ONE, i.e. it is not
                               allowed to force the routine to obtain orthogonality
                               below EPSILON.
                     On exit,
                     RWORK(1) = SCALE is the scaling factor such that SCALE*SVA(1:N)
                               are the computed singular values of A.
                               (See description of SVA().)
                     RWORK(2) = NINT(RWORK(2)) is the number of the computed nonzero
                               singular values.
                     RWORK(3) = NINT(RWORK(3)) is the number of the computed singular
                               values that are larger than the underflow threshold.
                     RWORK(4) = NINT(RWORK(4)) is the number of sweeps of Jacobi
                               rotations needed for numerical convergence.
                     RWORK(5) = max_{i.NE.j} |COS(A(:,i),A(:,j))| in the last sweep.
                               This is useful information in cases when ZGESVJ did
                               not converge, as it can be used to estimate whether
                               the output is still useful and for post festum analysis.
                     RWORK(6) = the largest absolute value over all sines of the
                               Jacobi rotation angles in the last sweep. It can be
                               useful for a post festum analysis.
                    If on entry LRWORK = -1, then a workspace query is assumed and
                    no computation is done; RWORK(1) is set to the minial (and optimal)
                    length of RWORK.

           LRWORK

                    LRWORK is INTEGER
                    Length of RWORK, LRWORK >= MAX(6,N).

           INFO

                     INFO is INTEGER
                     = 0:  successful exit.
                     < 0:  if INFO = -i, then the i-th argument had an illegal value
                     > 0:  ZGESVJ did not converge in the maximal allowed number
                           (NSWEEP=30) of sweeps. The output may still be useful.
                           See the description of RWORK.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

            The orthogonal N-by-N matrix V is obtained as a product of Jacobi plane
            rotations. In the case of underflow of the tangent of the Jacobi angle, a
            modified Jacobi transformation of Drmac [3] is used. Pivot strategy uses
            column interchanges of de Rijk [1]. The relative accuracy of the computed
            singular values and the accuracy of the computed singular vectors (in
            angle metric) is as guaranteed by the theory of Demmel and Veselic [2].
            The condition number that determines the accuracy in the full rank case
            is essentially min_{D=diag} kappa(A*D), where kappa(.) is the
            spectral condition number. The best performance of this Jacobi SVD
            procedure is achieved if used in an  accelerated version of Drmac and
            Veselic [4,5], and it is the kernel routine in the SIGMA library [6].
            Some tuning parameters (marked with [TP]) are available for the
            implementer.
            The computational range for the nonzero singular values is the  machine
            number interval ( UNDERFLOW , OVERFLOW ). In extreme cases, even
            denormalized singular values can be computed with the corresponding
            gradual loss of accurate digits.

       Contributor:

             ============

             Zlatko Drmac (Zagreb, Croatia)

       References:

            [1] P. P. M. De Rijk: A one-sided Jacobi algorithm for computing the
               singular value decomposition on a vector computer.
               SIAM J. Sci. Stat. Comp., Vol. 10 (1998), pp. 359-371.
            [2] J. Demmel and K. Veselic: Jacobi method is more accurate than QR.
            [3] Z. Drmac: Implementation of Jacobi rotations for accurate singular
               value computation in floating point arithmetic.
               SIAM J. Sci. Comp., Vol. 18 (1997), pp. 1200-1222.
            [4] Z. Drmac and K. Veselic: New fast and accurate Jacobi SVD algorithm I.
               SIAM J. Matrix Anal. Appl. Vol. 35, No. 2 (2008), pp. 1322-1342.
               LAPACK Working note 169.
            [5] Z. Drmac and K. Veselic: New fast and accurate Jacobi SVD algorithm II.
               SIAM J. Matrix Anal. Appl. Vol. 35, No. 2 (2008), pp. 1343-1362.
               LAPACK Working note 170.
            [6] Z. Drmac: SIGMA - mathematical software library for accurate SVD, PSV,
               QSVD, (H,K)-SVD computations.
               Department of Mathematics, University of Zagreb, 2008, 2015.

       Bugs, examples and comments:

             ===========================
             Please report all bugs and send interesting test examples and comments to
             drmac@math.hr. Thank you.

   subroutine zgetf2 (integer M, integer N, complex*16, dimension( lda, * ) A, integer LDA,
       integer, dimension( * ) IPIV, integer INFO)
       ZGETF2 computes the LU factorization of a general m-by-n matrix using partial pivoting
       with row interchanges (unblocked algorithm).

       Purpose:

            ZGETF2 computes an LU factorization of a general m-by-n matrix A
            using partial pivoting with row interchanges.

            The factorization has the form
               A = P * L * U
            where P is a permutation matrix, L is lower triangular with unit
            diagonal elements (lower trapezoidal if m > n), and U is upper
            triangular (upper trapezoidal if m < n).

            This is the right-looking Level 2 BLAS version of the algorithm.

       Parameters
           M

                     M is INTEGER
                     The number of rows of the matrix A.  M >= 0.

           N

                     N is INTEGER
                     The number of columns of the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the m by n matrix to be factored.
                     On exit, the factors L and U from the factorization
                     A = P*L*U; the unit diagonal elements of L are not stored.

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,M).

           IPIV

                     IPIV is INTEGER array, dimension (min(M,N))
                     The pivot indices; for 1 <= i <= min(M,N), row i of the
                     matrix was interchanged with row IPIV(i).

           INFO

                     INFO is INTEGER
                     = 0: successful exit
                     < 0: if INFO = -k, the k-th argument had an illegal value
                     > 0: if INFO = k, U(k,k) is exactly zero. The factorization
                          has been completed, but the factor U is exactly
                          singular, and division by zero will occur if it is used
                          to solve a system of equations.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

   subroutine zgetrf (integer M, integer N, complex*16, dimension( lda, * ) A, integer LDA,
       integer, dimension( * ) IPIV, integer INFO)
       ZGETRF

       Purpose:

            ZGETRF computes an LU factorization of a general M-by-N matrix A
            using partial pivoting with row interchanges.

            The factorization has the form
               A = P * L * U
            where P is a permutation matrix, L is lower triangular with unit
            diagonal elements (lower trapezoidal if m > n), and U is upper
            triangular (upper trapezoidal if m < n).

            This is the right-looking Level 3 BLAS version of the algorithm.

       Parameters
           M

                     M is INTEGER
                     The number of rows of the matrix A.  M >= 0.

           N

                     N is INTEGER
                     The number of columns of the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the M-by-N matrix to be factored.
                     On exit, the factors L and U from the factorization
                     A = P*L*U; the unit diagonal elements of L are not stored.

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,M).

           IPIV

                     IPIV is INTEGER array, dimension (min(M,N))
                     The pivot indices; for 1 <= i <= min(M,N), row i of the
                     matrix was interchanged with row IPIV(i).

           INFO

                     INFO is INTEGER
                     = 0:  successful exit
                     < 0:  if INFO = -i, the i-th argument had an illegal value
                     > 0:  if INFO = i, U(i,i) is exactly zero. The factorization
                           has been completed, but the factor U is exactly
                           singular, and division by zero will occur if it is used
                           to solve a system of equations.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

   recursive subroutine zgetrf2 (integer M, integer N, complex*16, dimension( lda, * ) A, integer
       LDA, integer, dimension( * ) IPIV, integer INFO)
       ZGETRF2

       Purpose:

            ZGETRF2 computes an LU factorization of a general M-by-N matrix A
            using partial pivoting with row interchanges.

            The factorization has the form
               A = P * L * U
            where P is a permutation matrix, L is lower triangular with unit
            diagonal elements (lower trapezoidal if m > n), and U is upper
            triangular (upper trapezoidal if m < n).

            This is the recursive version of the algorithm. It divides
            the matrix into four submatrices:

                   [  A11 | A12  ]  where A11 is n1 by n1 and A22 is n2 by n2
               A = [ -----|----- ]  with n1 = min(m,n)/2
                   [  A21 | A22  ]       n2 = n-n1

                                                  [ A11 ]
            The subroutine calls itself to factor [ --- ],
                                                  [ A12 ]
                            [ A12 ]
            do the swaps on [ --- ], solve A12, update A22,
                            [ A22 ]

            then calls itself to factor A22 and do the swaps on A21.

       Parameters
           M

                     M is INTEGER
                     The number of rows of the matrix A.  M >= 0.

           N

                     N is INTEGER
                     The number of columns of the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the M-by-N matrix to be factored.
                     On exit, the factors L and U from the factorization
                     A = P*L*U; the unit diagonal elements of L are not stored.

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,M).

           IPIV

                     IPIV is INTEGER array, dimension (min(M,N))
                     The pivot indices; for 1 <= i <= min(M,N), row i of the
                     matrix was interchanged with row IPIV(i).

           INFO

                     INFO is INTEGER
                     = 0:  successful exit
                     < 0:  if INFO = -i, the i-th argument had an illegal value
                     > 0:  if INFO = i, U(i,i) is exactly zero. The factorization
                           has been completed, but the factor U is exactly
                           singular, and division by zero will occur if it is used
                           to solve a system of equations.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

   subroutine zgetri (integer N, complex*16, dimension( lda, * ) A, integer LDA, integer,
       dimension( * ) IPIV, complex*16, dimension( * ) WORK, integer LWORK, integer INFO)
       ZGETRI

       Purpose:

            ZGETRI computes the inverse of a matrix using the LU factorization
            computed by ZGETRF.

            This method inverts U and then computes inv(A) by solving the system
            inv(A)*L = inv(U) for inv(A).

       Parameters
           N

                     N is INTEGER
                     The order of the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the factors L and U from the factorization
                     A = P*L*U as computed by ZGETRF.
                     On exit, if INFO = 0, the inverse of the original matrix A.

           LDA

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

           IPIV

                     IPIV is INTEGER array, dimension (N)
                     The pivot indices from ZGETRF; for 1<=i<=N, row i of the
                     matrix was interchanged with row IPIV(i).

           WORK

                     WORK is COMPLEX*16 array, dimension (MAX(1,LWORK))
                     On exit, if INFO=0, then WORK(1) returns the optimal LWORK.

           LWORK

                     LWORK is INTEGER
                     The dimension of the array WORK.  LWORK >= max(1,N).
                     For optimal performance LWORK >= N*NB, where NB is
                     the optimal blocksize returned by ILAENV.

                     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.

           INFO

                     INFO is INTEGER
                     = 0:  successful exit
                     < 0:  if INFO = -i, the i-th argument had an illegal value
                     > 0:  if INFO = i, U(i,i) is exactly zero; the matrix is
                           singular and its inverse could not be computed.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

   subroutine zgetrs (character TRANS, integer N, integer NRHS, complex*16, dimension( lda, * )
       A, integer LDA, integer, dimension( * ) IPIV, complex*16, dimension( ldb, * ) B, integer
       LDB, integer INFO)
       ZGETRS

       Purpose:

            ZGETRS solves a system of linear equations
               A * X = B,  A**T * X = B,  or  A**H * X = B
            with a general N-by-N matrix A using the LU factorization computed
            by ZGETRF.

       Parameters
           TRANS

                     TRANS is CHARACTER*1
                     Specifies the form of the system of equations:
                     = 'N':  A * X = B     (No transpose)
                     = 'T':  A**T * X = B  (Transpose)
                     = 'C':  A**H * X = B  (Conjugate transpose)

           N

                     N is INTEGER
                     The order of the matrix A.  N >= 0.

           NRHS

                     NRHS is INTEGER
                     The number of right hand sides, i.e., the number of columns
                     of the matrix B.  NRHS >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     The factors L and U from the factorization A = P*L*U
                     as computed by ZGETRF.

           LDA

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

           IPIV

                     IPIV is INTEGER array, dimension (N)
                     The pivot indices from ZGETRF; for 1<=i<=N, row i of the
                     matrix was interchanged with row IPIV(i).

           B

                     B is COMPLEX*16 array, dimension (LDB,NRHS)
                     On entry, the right hand side matrix B.
                     On exit, the solution matrix X.

           LDB

                     LDB is INTEGER
                     The leading dimension of the array B.  LDB >= max(1,N).

           INFO

                     INFO is INTEGER
                     = 0:  successful exit
                     < 0:  if INFO = -i, the i-th argument had an illegal value

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

   subroutine zhgeqz (character JOB, character COMPQ, character COMPZ, integer N, integer ILO,
       integer IHI, complex*16, dimension( ldh, * ) H, integer LDH, complex*16, dimension( ldt, *
       ) T, integer LDT, complex*16, dimension( * ) ALPHA, complex*16, dimension( * ) BETA,
       complex*16, dimension( ldq, * ) Q, integer LDQ, complex*16, dimension( ldz, * ) Z, integer
       LDZ, complex*16, dimension( * ) WORK, integer LWORK, double precision, dimension( * )
       RWORK, integer INFO)
       ZHGEQZ

       Purpose:

            ZHGEQZ computes the eigenvalues of a complex matrix pair (H,T),
            where H is an upper Hessenberg matrix and T is upper triangular,
            using the single-shift QZ method.
            Matrix pairs of this type are produced by the reduction to
            generalized upper Hessenberg form of a complex matrix pair (A,B):

               A = Q1*H*Z1**H,  B = Q1*T*Z1**H,

            as computed by ZGGHRD.

            If JOB='S', then the Hessenberg-triangular pair (H,T) is
            also reduced to generalized Schur form,

               H = Q*S*Z**H,  T = Q*P*Z**H,

            where Q and Z are unitary matrices and S and P are upper triangular.

            Optionally, the unitary matrix Q from the generalized Schur
            factorization may be postmultiplied into an input matrix Q1, and the
            unitary matrix Z may be postmultiplied into an input matrix Z1.
            If Q1 and Z1 are the unitary matrices from ZGGHRD that reduced
            the matrix pair (A,B) to generalized Hessenberg form, then the output
            matrices Q1*Q and Z1*Z are the unitary factors from the generalized
            Schur factorization of (A,B):

               A = (Q1*Q)*S*(Z1*Z)**H,  B = (Q1*Q)*P*(Z1*Z)**H.

            To avoid overflow, eigenvalues of the matrix pair (H,T)
            (equivalently, of (A,B)) are computed as a pair of complex values
            (alpha,beta).  If beta is nonzero, lambda = alpha / beta is an
            eigenvalue of the generalized nonsymmetric eigenvalue problem (GNEP)
               A*x = lambda*B*x
            and if alpha is nonzero, mu = beta / alpha is an eigenvalue of the
            alternate form of the GNEP
               mu*A*y = B*y.
            The values of alpha and beta for the i-th eigenvalue can be read
            directly from the generalized Schur form:  alpha = S(i,i),
            beta = P(i,i).

            Ref: C.B. Moler & G.W. Stewart, 'An Algorithm for Generalized Matrix
                 Eigenvalue Problems', SIAM J. Numer. Anal., 10(1973),
                 pp. 241--256.

       Parameters
           JOB

                     JOB is CHARACTER*1
                     = 'E': Compute eigenvalues only;
                     = 'S': Computer eigenvalues and the Schur form.

           COMPQ

                     COMPQ is CHARACTER*1
                     = 'N': Left Schur vectors (Q) are not computed;
                     = 'I': Q is initialized to the unit matrix and the matrix Q
                            of left Schur vectors of (H,T) is returned;
                     = 'V': Q must contain a unitary matrix Q1 on entry and
                            the product Q1*Q is returned.

           COMPZ

                     COMPZ is CHARACTER*1
                     = 'N': Right Schur vectors (Z) are not computed;
                     = 'I': Q is initialized to the unit matrix and the matrix Z
                            of right Schur vectors of (H,T) is returned;
                     = 'V': Z must contain a unitary matrix Z1 on entry and
                            the product Z1*Z is returned.

           N

                     N is INTEGER
                     The order of the matrices H, T, Q, and Z.  N >= 0.

           ILO

                     ILO is INTEGER

           IHI

                     IHI is INTEGER
                     ILO and IHI mark the rows and columns of H which are in
                     Hessenberg form.  It is assumed that A is already upper
                     triangular in rows and columns 1:ILO-1 and IHI+1:N.
                     If N > 0, 1 <= ILO <= IHI <= N; if N = 0, ILO=1 and IHI=0.

           H

                     H is COMPLEX*16 array, dimension (LDH, N)
                     On entry, the N-by-N upper Hessenberg matrix H.
                     On exit, if JOB = 'S', H contains the upper triangular
                     matrix S from the generalized Schur factorization.
                     If JOB = 'E', the diagonal of H matches that of S, but
                     the rest of H is unspecified.

           LDH

                     LDH is INTEGER
                     The leading dimension of the array H.  LDH >= max( 1, N ).

           T

                     T is COMPLEX*16 array, dimension (LDT, N)
                     On entry, the N-by-N upper triangular matrix T.
                     On exit, if JOB = 'S', T contains the upper triangular
                     matrix P from the generalized Schur factorization.
                     If JOB = 'E', the diagonal of T matches that of P, but
                     the rest of T is unspecified.

           LDT

                     LDT is INTEGER
                     The leading dimension of the array T.  LDT >= max( 1, N ).

           ALPHA

                     ALPHA is COMPLEX*16 array, dimension (N)
                     The complex scalars alpha that define the eigenvalues of
                     GNEP.  ALPHA(i) = S(i,i) in the generalized Schur
                     factorization.

           BETA

                     BETA is COMPLEX*16 array, dimension (N)
                     The real non-negative scalars beta that define the
                     eigenvalues of GNEP.  BETA(i) = P(i,i) in the generalized
                     Schur factorization.

                     Together, the quantities alpha = ALPHA(j) and beta = BETA(j)
                     represent the j-th eigenvalue of the matrix pair (A,B), in
                     one of the forms lambda = alpha/beta or mu = beta/alpha.
                     Since either lambda or mu may overflow, they should not,
                     in general, be computed.

           Q

                     Q is COMPLEX*16 array, dimension (LDQ, N)
                     On entry, if COMPQ = 'V', the unitary matrix Q1 used in the
                     reduction of (A,B) to generalized Hessenberg form.
                     On exit, if COMPQ = 'I', the unitary matrix of left Schur
                     vectors of (H,T), and if COMPQ = 'V', the unitary matrix of
                     left Schur vectors of (A,B).
                     Not referenced if COMPQ = 'N'.

           LDQ

                     LDQ is INTEGER
                     The leading dimension of the array Q.  LDQ >= 1.
                     If COMPQ='V' or 'I', then LDQ >= N.

           Z

                     Z is COMPLEX*16 array, dimension (LDZ, N)
                     On entry, if COMPZ = 'V', the unitary matrix Z1 used in the
                     reduction of (A,B) to generalized Hessenberg form.
                     On exit, if COMPZ = 'I', the unitary matrix of right Schur
                     vectors of (H,T), and if COMPZ = 'V', the unitary matrix of
                     right Schur vectors of (A,B).
                     Not referenced if COMPZ = 'N'.

           LDZ

                     LDZ is INTEGER
                     The leading dimension of the array Z.  LDZ >= 1.
                     If COMPZ='V' or 'I', then LDZ >= N.

           WORK

                     WORK is COMPLEX*16 array, dimension (MAX(1,LWORK))
                     On exit, if INFO >= 0, WORK(1) returns the optimal LWORK.

           LWORK

                     LWORK is INTEGER
                     The dimension of the array WORK.  LWORK >= max(1,N).

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

           RWORK

                     RWORK is DOUBLE PRECISION array, dimension (N)

           INFO

                     INFO is INTEGER
                     = 0: successful exit
                     < 0: if INFO = -i, the i-th argument had an illegal value
                     = 1,...,N: the QZ iteration did not converge.  (H,T) is not
                                in Schur form, but ALPHA(i) and BETA(i),
                                i=INFO+1,...,N should be correct.
                     = N+1,...,2*N: the shift calculation failed.  (H,T) is not
                                in Schur form, but ALPHA(i) and BETA(i),
                                i=INFO-N+1,...,N should be correct.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Further Details:

             We assume that complex ABS works as long as its value is less than
             overflow.

   subroutine zla_geamv (integer TRANS, integer M, integer N, double precision ALPHA, complex*16,
       dimension( lda, * ) A, integer LDA, complex*16, dimension( * ) X, integer INCX, double
       precision BETA, double precision, dimension( * ) Y, integer INCY)
       ZLA_GEAMV computes a matrix-vector product using a general matrix to calculate error
       bounds.

       Purpose:

            ZLA_GEAMV  performs one of the matrix-vector operations

                    y := alpha*abs(A)*abs(x) + beta*abs(y),
               or   y := alpha*abs(A)**T*abs(x) + beta*abs(y),

            where alpha and beta are scalars, x and y are vectors and A is an
            m by n matrix.

            This function is primarily used in calculating error bounds.
            To protect against underflow during evaluation, components in
            the resulting vector are perturbed away from zero by (N+1)
            times the underflow threshold.  To prevent unnecessarily large
            errors for block-structure embedded in general matrices,
            'symbolically' zero components are not perturbed.  A zero
            entry is considered 'symbolic' if all multiplications involved
            in computing that entry have at least one zero multiplicand.

       Parameters
           TRANS

                     TRANS is INTEGER
                      On entry, TRANS specifies the operation to be performed as
                      follows:

                        BLAS_NO_TRANS      y := alpha*abs(A)*abs(x) + beta*abs(y)
                        BLAS_TRANS         y := alpha*abs(A**T)*abs(x) + beta*abs(y)
                        BLAS_CONJ_TRANS    y := alpha*abs(A**T)*abs(x) + beta*abs(y)

                      Unchanged on exit.

           M

                     M is INTEGER
                      On entry, M specifies the number of rows of the matrix A.
                      M must be at least zero.
                      Unchanged on exit.

           N

                     N is INTEGER
                      On entry, N specifies the number of columns of the matrix A.
                      N must be at least zero.
                      Unchanged on exit.

           ALPHA

                     ALPHA is DOUBLE PRECISION
                      On entry, ALPHA specifies the scalar alpha.
                      Unchanged on exit.

           A

                     A is COMPLEX*16 array, dimension ( LDA, n )
                      Before entry, the leading m by n part of the array A must
                      contain the matrix of coefficients.
                      Unchanged on exit.

           LDA

                     LDA is INTEGER
                      On entry, LDA specifies the first dimension of A as declared
                      in the calling (sub) program. LDA must be at least
                      max( 1, m ).
                      Unchanged on exit.

           X

                     X is COMPLEX*16 array, dimension at least
                      ( 1 + ( n - 1 )*abs( INCX ) ) when TRANS = 'N' or 'n'
                      and at least
                      ( 1 + ( m - 1 )*abs( INCX ) ) otherwise.
                      Before entry, the incremented array X must contain the
                      vector x.
                      Unchanged on exit.

           INCX

                     INCX is INTEGER
                      On entry, INCX specifies the increment for the elements of
                      X. INCX must not be zero.
                      Unchanged on exit.

           BETA

                     BETA is DOUBLE PRECISION
                      On entry, BETA specifies the scalar beta. When BETA is
                      supplied as zero then Y need not be set on input.
                      Unchanged on exit.

           Y

                     Y is DOUBLE PRECISION array, dimension
                      ( 1 + ( m - 1 )*abs( INCY ) ) when TRANS = 'N' or 'n'
                      and at least
                      ( 1 + ( n - 1 )*abs( INCY ) ) otherwise.
                      Before entry with BETA non-zero, the incremented array Y
                      must contain the vector y. On exit, Y is overwritten by the
                      updated vector y.

           INCY

                     INCY is INTEGER
                      On entry, INCY specifies the increment for the elements of
                      Y. INCY must not be zero.
                      Unchanged on exit.

             Level 2 Blas routine.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

   double precision function zla_gercond_c (character TRANS, integer N, complex*16, dimension(
       lda, * ) A, integer LDA, complex*16, dimension( ldaf, * ) AF, integer LDAF, integer,
       dimension( * ) IPIV, double precision, dimension( * ) C, logical CAPPLY, integer INFO,
       complex*16, dimension( * ) WORK, double precision, dimension( * ) RWORK)
       ZLA_GERCOND_C computes the infinity norm condition number of op(A)*inv(diag(c)) for
       general matrices.

       Purpose:

               ZLA_GERCOND_C computes the infinity norm condition number of
               op(A) * inv(diag(C)) where C is a DOUBLE PRECISION vector.

       Parameters
           TRANS

                     TRANS is CHARACTER*1
                Specifies the form of the system of equations:
                  = 'N':  A * X = B     (No transpose)
                  = 'T':  A**T * X = B  (Transpose)
                  = 'C':  A**H * X = B  (Conjugate Transpose = Transpose)

           N

                     N is INTEGER
                The number of linear equations, i.e., the order of the
                matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                On entry, the N-by-N matrix A

           LDA

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

           AF

                     AF is COMPLEX*16 array, dimension (LDAF,N)
                The factors L and U from the factorization
                A = P*L*U as computed by ZGETRF.

           LDAF

                     LDAF is INTEGER
                The leading dimension of the array AF.  LDAF >= max(1,N).

           IPIV

                     IPIV is INTEGER array, dimension (N)
                The pivot indices from the factorization A = P*L*U
                as computed by ZGETRF; row i of the matrix was interchanged
                with row IPIV(i).

           C

                     C is DOUBLE PRECISION array, dimension (N)
                The vector C in the formula op(A) * inv(diag(C)).

           CAPPLY

                     CAPPLY is LOGICAL
                If .TRUE. then access the vector C in the formula above.

           INFO

                     INFO is INTEGER
                  = 0:  Successful exit.
                i > 0:  The ith argument is invalid.

           WORK

                     WORK is COMPLEX*16 array, dimension (2*N).
                Workspace.

           RWORK

                     RWORK is DOUBLE PRECISION array, dimension (N).
                Workspace.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

   double precision function zla_gercond_x (character TRANS, integer N, complex*16, dimension(
       lda, * ) A, integer LDA, complex*16, dimension( ldaf, * ) AF, integer LDAF, integer,
       dimension( * ) IPIV, complex*16, dimension( * ) X, integer INFO, complex*16, dimension( *
       ) WORK, double precision, dimension( * ) RWORK)
       ZLA_GERCOND_X computes the infinity norm condition number of op(A)*diag(x) for general
       matrices.

       Purpose:

               ZLA_GERCOND_X computes the infinity norm condition number of
               op(A) * diag(X) where X is a COMPLEX*16 vector.

       Parameters
           TRANS

                     TRANS is CHARACTER*1
                Specifies the form of the system of equations:
                  = 'N':  A * X = B     (No transpose)
                  = 'T':  A**T * X = B  (Transpose)
                  = 'C':  A**H * X = B  (Conjugate Transpose = Transpose)

           N

                     N is INTEGER
                The number of linear equations, i.e., the order of the
                matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                On entry, the N-by-N matrix A.

           LDA

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

           AF

                     AF is COMPLEX*16 array, dimension (LDAF,N)
                The factors L and U from the factorization
                A = P*L*U as computed by ZGETRF.

           LDAF

                     LDAF is INTEGER
                The leading dimension of the array AF.  LDAF >= max(1,N).

           IPIV

                     IPIV is INTEGER array, dimension (N)
                The pivot indices from the factorization A = P*L*U
                as computed by ZGETRF; row i of the matrix was interchanged
                with row IPIV(i).

           X

                     X is COMPLEX*16 array, dimension (N)
                The vector X in the formula op(A) * diag(X).

           INFO

                     INFO is INTEGER
                  = 0:  Successful exit.
                i > 0:  The ith argument is invalid.

           WORK

                     WORK is COMPLEX*16 array, dimension (2*N).
                Workspace.

           RWORK

                     RWORK is DOUBLE PRECISION array, dimension (N).
                Workspace.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

   subroutine zla_gerfsx_extended (integer PREC_TYPE, integer TRANS_TYPE, integer N, integer
       NRHS, complex*16, dimension( lda, * ) A, integer LDA, complex*16, dimension( ldaf, * ) AF,
       integer LDAF, integer, dimension( * ) IPIV, logical COLEQU, double precision, dimension( *
       ) C, complex*16, dimension( ldb, * ) B, integer LDB, complex*16, dimension( ldy, * ) Y,
       integer LDY, double precision, dimension( * ) BERR_OUT, integer N_NORMS, double precision,
       dimension( nrhs, * ) ERRS_N, double precision, dimension( nrhs, * ) ERRS_C, complex*16,
       dimension( * ) RES, double precision, dimension( * ) AYB, complex*16, dimension( * ) DY,
       complex*16, dimension( * ) Y_TAIL, double precision RCOND, integer ITHRESH, double
       precision RTHRESH, double precision DZ_UB, logical IGNORE_CWISE, integer INFO)
       ZLA_GERFSX_EXTENDED

       Purpose:

            ZLA_GERFSX_EXTENDED improves the computed solution to a system of
            linear equations by performing extra-precise iterative refinement
            and provides error bounds and backward error estimates for the solution.
            This subroutine is called by ZGERFSX to perform iterative refinement.
            In addition to normwise error bound, the code provides maximum
            componentwise error bound if possible. See comments for ERRS_N
            and ERRS_C for details of the error bounds. Note that this
            subroutine is only responsible for setting the second fields of
            ERRS_N and ERRS_C.

       Parameters
           PREC_TYPE

                     PREC_TYPE is INTEGER
                Specifies the intermediate precision to be used in refinement.
                The value is defined by ILAPREC(P) where P is a CHARACTER and P
                     = 'S':  Single
                     = 'D':  Double
                     = 'I':  Indigenous
                     = 'X' or 'E':  Extra

           TRANS_TYPE

                     TRANS_TYPE is INTEGER
                Specifies the transposition operation on A.
                The value is defined by ILATRANS(T) where T is a CHARACTER and T
                     = 'N':  No transpose
                     = 'T':  Transpose
                     = 'C':  Conjugate transpose

           N

                     N is INTEGER
                The number of linear equations, i.e., the order of the
                matrix A.  N >= 0.

           NRHS

                     NRHS is INTEGER
                The number of right-hand-sides, i.e., the number of columns of the
                matrix B.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                On entry, the N-by-N matrix A.

           LDA

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

           AF

                     AF is COMPLEX*16 array, dimension (LDAF,N)
                The factors L and U from the factorization
                A = P*L*U as computed by ZGETRF.

           LDAF

                     LDAF is INTEGER
                The leading dimension of the array AF.  LDAF >= max(1,N).

           IPIV

                     IPIV is INTEGER array, dimension (N)
                The pivot indices from the factorization A = P*L*U
                as computed by ZGETRF; row i of the matrix was interchanged
                with row IPIV(i).

           COLEQU

                     COLEQU is LOGICAL
                If .TRUE. then column equilibration was done to A before calling
                this routine. This is needed to compute the solution and error
                bounds correctly.

           C

                     C is DOUBLE PRECISION array, dimension (N)
                The column scale factors for A. If COLEQU = .FALSE., C
                is not accessed. If C is input, each element of C should be a power
                of the radix to ensure a reliable solution and error estimates.
                Scaling by powers of the radix does not cause rounding errors unless
                the result underflows or overflows. Rounding errors during scaling
                lead to refining with a matrix that is not equivalent to the
                input matrix, producing error estimates that may not be
                reliable.

           B

                     B is COMPLEX*16 array, dimension (LDB,NRHS)
                The right-hand-side matrix B.

           LDB

                     LDB is INTEGER
                The leading dimension of the array B.  LDB >= max(1,N).

           Y

                     Y is COMPLEX*16 array, dimension (LDY,NRHS)
                On entry, the solution matrix X, as computed by ZGETRS.
                On exit, the improved solution matrix Y.

           LDY

                     LDY is INTEGER
                The leading dimension of the array Y.  LDY >= max(1,N).

           BERR_OUT

                     BERR_OUT is DOUBLE PRECISION array, dimension (NRHS)
                On exit, BERR_OUT(j) contains the componentwise relative backward
                error for right-hand-side j from the formula
                    max(i) ( abs(RES(i)) / ( abs(op(A_s))*abs(Y) + abs(B_s) )(i) )
                where abs(Z) is the componentwise absolute value of the matrix
                or vector Z. This is computed by ZLA_LIN_BERR.

           N_NORMS

                     N_NORMS is INTEGER
                Determines which error bounds to return (see ERRS_N
                and ERRS_C).
                If N_NORMS >= 1 return normwise error bounds.
                If N_NORMS >= 2 return componentwise error bounds.

           ERRS_N

                     ERRS_N is DOUBLE PRECISION array, dimension (NRHS, N_ERR_BNDS)
                For each right-hand side, this array contains information about
                various error bounds and condition numbers corresponding to the
                normwise relative error, which is defined as follows:

                Normwise relative error in the ith solution vector:
                        max_j (abs(XTRUE(j,i) - X(j,i)))
                       ------------------------------
                             max_j abs(X(j,i))

                The array is indexed by the type of error information as described
                below. There currently are up to three pieces of information
                returned.

                The first index in ERRS_N(i,:) corresponds to the ith
                right-hand side.

                The second index in ERRS_N(:,err) contains the following
                three fields:
                err = 1 'Trust/don't trust' boolean. Trust the answer if the
                         reciprocal condition number is less than the threshold
                         sqrt(n) * slamch('Epsilon').

                err = 2 'Guaranteed' error bound: The estimated forward error,
                         almost certainly within a factor of 10 of the true error
                         so long as the next entry is greater than the threshold
                         sqrt(n) * slamch('Epsilon'). This error bound should only
                         be trusted if the previous boolean is true.

                err = 3  Reciprocal condition number: Estimated normwise
                         reciprocal condition number.  Compared with the threshold
                         sqrt(n) * slamch('Epsilon') to determine if the error
                         estimate is 'guaranteed'. These reciprocal condition
                         numbers are 1 / (norm(Z^{-1},inf) * norm(Z,inf)) for some
                         appropriately scaled matrix Z.
                         Let Z = S*A, where S scales each row by a power of the
                         radix so all absolute row sums of Z are approximately 1.

                This subroutine is only responsible for setting the second field
                above.
                See Lapack Working Note 165 for further details and extra
                cautions.

           ERRS_C

                     ERRS_C is DOUBLE PRECISION array, dimension (NRHS, N_ERR_BNDS)
                For each right-hand side, this array contains information about
                various error bounds and condition numbers corresponding to the
                componentwise relative error, which is defined as follows:

                Componentwise relative error in the ith solution vector:
                               abs(XTRUE(j,i) - X(j,i))
                        max_j ----------------------
                                    abs(X(j,i))

                The array is indexed by the right-hand side i (on which the
                componentwise relative error depends), and the type of error
                information as described below. There currently are up to three
                pieces of information returned for each right-hand side. If
                componentwise accuracy is not requested (PARAMS(3) = 0.0), then
                ERRS_C is not accessed.  If N_ERR_BNDS < 3, then at most
                the first (:,N_ERR_BNDS) entries are returned.

                The first index in ERRS_C(i,:) corresponds to the ith
                right-hand side.

                The second index in ERRS_C(:,err) contains the following
                three fields:
                err = 1 'Trust/don't trust' boolean. Trust the answer if the
                         reciprocal condition number is less than the threshold
                         sqrt(n) * slamch('Epsilon').

                err = 2 'Guaranteed' error bound: The estimated forward error,
                         almost certainly within a factor of 10 of the true error
                         so long as the next entry is greater than the threshold
                         sqrt(n) * slamch('Epsilon'). This error bound should only
                         be trusted if the previous boolean is true.

                err = 3  Reciprocal condition number: Estimated componentwise
                         reciprocal condition number.  Compared with the threshold
                         sqrt(n) * slamch('Epsilon') to determine if the error
                         estimate is 'guaranteed'. These reciprocal condition
                         numbers are 1 / (norm(Z^{-1},inf) * norm(Z,inf)) for some
                         appropriately scaled matrix Z.
                         Let Z = S*(A*diag(x)), where x is the solution for the
                         current right-hand side and S scales each row of
                         A*diag(x) by a power of the radix so all absolute row
                         sums of Z are approximately 1.

                This subroutine is only responsible for setting the second field
                above.
                See Lapack Working Note 165 for further details and extra
                cautions.

           RES

                     RES is COMPLEX*16 array, dimension (N)
                Workspace to hold the intermediate residual.

           AYB

                     AYB is DOUBLE PRECISION array, dimension (N)
                Workspace.

           DY

                     DY is COMPLEX*16 array, dimension (N)
                Workspace to hold the intermediate solution.

           Y_TAIL

                     Y_TAIL is COMPLEX*16 array, dimension (N)
                Workspace to hold the trailing bits of the intermediate solution.

           RCOND

                     RCOND is DOUBLE PRECISION
                Reciprocal scaled condition number.  This is an estimate of the
                reciprocal Skeel condition number of the matrix A after
                equilibration (if done).  If this is less than the machine
                precision (in particular, if it is zero), the matrix is singular
                to working precision.  Note that the error may still be small even
                if this number is very small and the matrix appears ill-
                conditioned.

           ITHRESH

                     ITHRESH is INTEGER
                The maximum number of residual computations allowed for
                refinement. The default is 10. For 'aggressive' set to 100 to
                permit convergence using approximate factorizations or
                factorizations other than LU. If the factorization uses a
                technique other than Gaussian elimination, the guarantees in
                ERRS_N and ERRS_C may no longer be trustworthy.

           RTHRESH

                     RTHRESH is DOUBLE PRECISION
                Determines when to stop refinement if the error estimate stops
                decreasing. Refinement will stop when the next solution no longer
                satisfies norm(dx_{i+1}) < RTHRESH * norm(dx_i) where norm(Z) is
                the infinity norm of Z. RTHRESH satisfies 0 < RTHRESH <= 1. The
                default value is 0.5. For 'aggressive' set to 0.9 to permit
                convergence on extremely ill-conditioned matrices. See LAWN 165
                for more details.

           DZ_UB

                     DZ_UB is DOUBLE PRECISION
                Determines when to start considering componentwise convergence.
                Componentwise convergence is only considered after each component
                of the solution Y is stable, which we define as the relative
                change in each component being less than DZ_UB. The default value
                is 0.25, requiring the first bit to be stable. See LAWN 165 for
                more details.

           IGNORE_CWISE

                     IGNORE_CWISE is LOGICAL
                If .TRUE. then ignore componentwise convergence. Default value
                is .FALSE..

           INFO

                     INFO is INTEGER
                  = 0:  Successful exit.
                  < 0:  if INFO = -i, the ith argument to ZGETRS had an illegal
                        value

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

   double precision function zla_gerpvgrw (integer N, integer NCOLS, complex*16, dimension( lda,
       * ) A, integer LDA, complex*16, dimension( ldaf, * ) AF, integer LDAF)
       ZLA_GERPVGRW multiplies a square real matrix by a complex matrix.

       Purpose:

            ZLA_GERPVGRW computes the reciprocal pivot growth factor
            norm(A)/norm(U). The 'max absolute element' norm is used. If this is
            much less than 1, the stability of the LU factorization of the
            (equilibrated) matrix A could be poor. This also means that the
            solution X, estimated condition numbers, and error bounds could be
            unreliable.

       Parameters
           N

                     N is INTEGER
                The number of linear equations, i.e., the order of the
                matrix A.  N >= 0.

           NCOLS

                     NCOLS is INTEGER
                The number of columns of the matrix A. NCOLS >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                On entry, the N-by-N matrix A.

           LDA

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

           AF

                     AF is COMPLEX*16 array, dimension (LDAF,N)
                The factors L and U from the factorization
                A = P*L*U as computed by ZGETRF.

           LDAF

                     LDAF is INTEGER
                The leading dimension of the array AF.  LDAF >= max(1,N).

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

   recursive subroutine zlaqz0 (character, intent(in) WANTS, character, intent(in) WANTQ,
       character, intent(in) WANTZ, integer, intent(in) N, integer, intent(in) ILO, integer,
       intent(in) IHI, complex*16, dimension( lda, * ), intent(inout) A, integer, intent(in) LDA,
       complex*16, dimension( ldb, * ), intent(inout) B, integer, intent(in) LDB, complex*16,
       dimension( * ), intent(inout) ALPHA, complex*16, dimension( * ), intent(inout) BETA,
       complex*16, dimension( ldq,         * ), intent(inout) Q, integer, intent(in) LDQ,
       complex*16, dimension( ldz, * ), intent(inout) Z, integer, intent(in) LDZ, complex*16,
       dimension( * ), intent(inout) WORK, integer, intent(in) LWORK, double precision,
       dimension( * ), intent(out) RWORK, integer, intent(in) REC, integer, intent(out) INFO)
       ZLAQZ0

       Purpose:

            ZLAQZ0 computes the eigenvalues of a real matrix pair (H,T),
            where H is an upper Hessenberg matrix and T is upper triangular,
            using the double-shift QZ method.
            Matrix pairs of this type are produced by the reduction to
            generalized upper Hessenberg form of a real matrix pair (A,B):

               A = Q1*H*Z1**H,  B = Q1*T*Z1**H,

            as computed by ZGGHRD.

            If JOB='S', then the Hessenberg-triangular pair (H,T) is
            also reduced to generalized Schur form,

               H = Q*S*Z**H,  T = Q*P*Z**H,

            where Q and Z are unitary matrices, P and S are an upper triangular
            matrices.

            Optionally, the unitary matrix Q from the generalized Schur
            factorization may be postmultiplied into an input matrix Q1, and the
            unitary matrix Z may be postmultiplied into an input matrix Z1.
            If Q1 and Z1 are the unitary matrices from ZGGHRD that reduced
            the matrix pair (A,B) to generalized upper Hessenberg form, then the
            output matrices Q1*Q and Z1*Z are the unitary factors from the
            generalized Schur factorization of (A,B):

               A = (Q1*Q)*S*(Z1*Z)**H,  B = (Q1*Q)*P*(Z1*Z)**H.

            To avoid overflow, eigenvalues of the matrix pair (H,T) (equivalently,
            of (A,B)) are computed as a pair of values (alpha,beta), where alpha is
            complex and beta real.
            If beta is nonzero, lambda = alpha / beta is an eigenvalue of the
            generalized nonsymmetric eigenvalue problem (GNEP)
               A*x = lambda*B*x
            and if alpha is nonzero, mu = beta / alpha is an eigenvalue of the
            alternate form of the GNEP
               mu*A*y = B*y.
            Eigenvalues can be read directly from the generalized Schur
            form:
              alpha = S(i,i), beta = P(i,i).

            Ref: C.B. Moler & G.W. Stewart, 'An Algorithm for Generalized Matrix
                 Eigenvalue Problems', SIAM J. Numer. Anal., 10(1973),
                 pp. 241--256.

            Ref: B. Kagstrom, D. Kressner, 'Multishift Variants of the QZ
                 Algorithm with Aggressive Early Deflation', SIAM J. Numer.
                 Anal., 29(2006), pp. 199--227.

            Ref: T. Steel, D. Camps, K. Meerbergen, R. Vandebril 'A multishift,
                 multipole rational QZ method with agressive early deflation'

       Parameters
           WANTS

                     WANTS is CHARACTER*1
                     = 'E': Compute eigenvalues only;
                     = 'S': Compute eigenvalues and the Schur form.

           WANTQ

                     WANTQ is CHARACTER*1
                     = 'N': Left Schur vectors (Q) are not computed;
                     = 'I': Q is initialized to the unit matrix and the matrix Q
                            of left Schur vectors of (A,B) is returned;
                     = 'V': Q must contain an unitary matrix Q1 on entry and
                            the product Q1*Q is returned.

           WANTZ

                     WANTZ is CHARACTER*1
                     = 'N': Right Schur vectors (Z) are not computed;
                     = 'I': Z is initialized to the unit matrix and the matrix Z
                            of right Schur vectors of (A,B) is returned;
                     = 'V': Z must contain an unitary matrix Z1 on entry and
                            the product Z1*Z is returned.

           N

                     N is INTEGER
                     The order of the matrices A, B, Q, and Z.  N >= 0.

           ILO

                     ILO is INTEGER

           IHI

                     IHI is INTEGER
                     ILO and IHI mark the rows and columns of A which are in
                     Hessenberg form.  It is assumed that A is already upper
                     triangular in rows and columns 1:ILO-1 and IHI+1:N.
                     If N > 0, 1 <= ILO <= IHI <= N; if N = 0, ILO=1 and IHI=0.

           A

                     A is COMPLEX*16 array, dimension (LDA, N)
                     On entry, the N-by-N upper Hessenberg matrix A.
                     On exit, if JOB = 'S', A contains the upper triangular
                     matrix S from the generalized Schur factorization.
                     If JOB = 'E', the diagonal blocks of A match those of S, but
                     the rest of A is unspecified.

           LDA

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

           B

                     B is COMPLEX*16 array, dimension (LDB, N)
                     On entry, the N-by-N upper triangular matrix B.
                     On exit, if JOB = 'S', B contains the upper triangular
                     matrix P from the generalized Schur factorization;
                     If JOB = 'E', the diagonal blocks of B match those of P, but
                     the rest of B is unspecified.

           LDB

                     LDB is INTEGER
                     The leading dimension of the array B.  LDB >= max( 1, N ).

           ALPHA

                     ALPHA is COMPLEX*16 array, dimension (N)
                     Each scalar alpha defining an eigenvalue
                     of GNEP.

           BETA

                     BETA is COMPLEX*16 array, dimension (N)
                     The scalars beta that define the eigenvalues of GNEP.
                     Together, the quantities alpha = ALPHA(j) and
                     beta = BETA(j) represent the j-th eigenvalue of the matrix
                     pair (A,B), in one of the forms lambda = alpha/beta or
                     mu = beta/alpha.  Since either lambda or mu may overflow,
                     they should not, in general, be computed.

           Q

                     Q is COMPLEX*16 array, dimension (LDQ, N)
                     On entry, if COMPQ = 'V', the unitary matrix Q1 used in
                     the reduction of (A,B) to generalized Hessenberg form.
                     On exit, if COMPQ = 'I', the unitary matrix of left Schur
                     vectors of (A,B), and if COMPQ = 'V', the unitary matrix
                     of left Schur vectors of (A,B).
                     Not referenced if COMPQ = 'N'.

           LDQ

                     LDQ is INTEGER
                     The leading dimension of the array Q.  LDQ >= 1.
                     If COMPQ='V' or 'I', then LDQ >= N.

           Z

                     Z is COMPLEX*16 array, dimension (LDZ, N)
                     On entry, if COMPZ = 'V', the unitary matrix Z1 used in
                     the reduction of (A,B) to generalized Hessenberg form.
                     On exit, if COMPZ = 'I', the unitary matrix of
                     right Schur vectors of (H,T), and if COMPZ = 'V', the
                     unitary matrix of right Schur vectors of (A,B).
                     Not referenced if COMPZ = 'N'.

           LDZ

                     LDZ is INTEGER
                     The leading dimension of the array Z.  LDZ >= 1.
                     If COMPZ='V' or 'I', then LDZ >= N.

           WORK

                     WORK is COMPLEX*16 array, dimension (MAX(1,LWORK))
                     On exit, if INFO >= 0, WORK(1) returns the optimal LWORK.

           RWORK

                     RWORK is DOUBLE PRECISION array, dimension (N)

           LWORK

                     LWORK is INTEGER
                     The dimension of the array WORK.  LWORK >= max(1,N).

                     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.

           REC

                     REC is INTEGER
                        REC indicates the current recursion level. Should be set
                        to 0 on first call.

           INFO

                     INFO is INTEGER
                     = 0: successful exit
                     < 0: if INFO = -i, the i-th argument had an illegal value
                     = 1,...,N: the QZ iteration did not converge.  (A,B) is not
                                in Schur form, but ALPHA(i) and
                                BETA(i), i=INFO+1,...,N should be correct.

       Author
           Thijs Steel, KU Leuven

       Date
           May 2020

   subroutine zlaqz1 (logical, intent(in) ILQ, logical, intent(in) ILZ, integer, intent(in) K,
       integer, intent(in) ISTARTM, integer, intent(in) ISTOPM, integer, intent(in) IHI,
       complex*16, dimension( lda, * ) A, integer, intent(in) LDA, complex*16, dimension( ldb, *
       ) B, integer, intent(in) LDB, integer, intent(in) NQ, integer, intent(in) QSTART,
       complex*16, dimension( ldq, * ) Q, integer, intent(in) LDQ, integer, intent(in) NZ,
       integer, intent(in) ZSTART, complex*16, dimension( ldz, * ) Z, integer, intent(in) LDZ)
       ZLAQZ1

       Purpose:

                 ZLAQZ1 chases a 1x1 shift bulge in a matrix pencil down a single position

       Parameters
           ILQ

                     ILQ is LOGICAL
                         Determines whether or not to update the matrix Q

           ILZ

                     ILZ is LOGICAL
                         Determines whether or not to update the matrix Z

           K

                     K is INTEGER
                         Index indicating the position of the bulge.
                         On entry, the bulge is located in
                         (A(k+1,k),B(k+1,k)).
                         On exit, the bulge is located in
                         (A(k+2,k+1),B(k+2,k+1)).

           ISTARTM

                     ISTARTM is INTEGER

           ISTOPM

                     ISTOPM is INTEGER
                         Updates to (A,B) are restricted to
                         (istartm:k+2,k:istopm). It is assumed
                         without checking that istartm <= k+1 and
                         k+2 <= istopm

           IHI

                     IHI is INTEGER

           A

                     A is COMPLEX*16 array, dimension (LDA,N)

           LDA

                     LDA is INTEGER
                         The leading dimension of A as declared in
                         the calling procedure.

           B

                     B is COMPLEX*16 array, dimension (LDB,N)

           LDB

                     LDB is INTEGER
                         The leading dimension of B as declared in
                         the calling procedure.

           NQ

                     NQ is INTEGER
                         The order of the matrix Q

           QSTART

                     QSTART is INTEGER
                         Start index of the matrix Q. Rotations are applied
                         To columns k+2-qStart:k+3-qStart of Q.

           Q

                     Q is COMPLEX*16 array, dimension (LDQ,NQ)

           LDQ

                     LDQ is INTEGER
                         The leading dimension of Q as declared in
                         the calling procedure.

           NZ

                     NZ is INTEGER
                         The order of the matrix Z

           ZSTART

                     ZSTART is INTEGER
                         Start index of the matrix Z. Rotations are applied
                         To columns k+1-qStart:k+2-qStart of Z.

           Z

                     Z is COMPLEX*16 array, dimension (LDZ,NZ)

           LDZ

                     LDZ is INTEGER
                         The leading dimension of Q as declared in
                         the calling procedure.

       Author
           Thijs Steel, KU Leuven

       Date
           May 2020

   recursive subroutine zlaqz2 (logical, intent(in) ILSCHUR, logical, intent(in) ILQ, logical,
       intent(in) ILZ, integer, intent(in) N, integer, intent(in) ILO, integer, intent(in) IHI,
       integer, intent(in) NW, complex*16, dimension( lda, * ), intent(inout) A, integer,
       intent(in) LDA, complex*16, dimension( ldb, * ), intent(inout) B, integer, intent(in) LDB,
       complex*16, dimension( ldq,         * ), intent(inout) Q, integer, intent(in) LDQ,
       complex*16, dimension( ldz, * ), intent(inout) Z, integer, intent(in) LDZ, integer,
       intent(out) NS, integer, intent(out) ND, complex*16, dimension( * ), intent(inout) ALPHA,
       complex*16, dimension( * ), intent(inout) BETA, complex*16, dimension( ldqc, * ) QC,
       integer, intent(in) LDQC, complex*16, dimension( ldzc, * ) ZC, integer, intent(in) LDZC,
       complex*16, dimension( * ) WORK, integer, intent(in) LWORK, double precision, dimension( *
       ) RWORK, integer, intent(in) REC, integer, intent(out) INFO)
       ZLAQZ2

       Purpose:

            ZLAQZ2 performs AED

       Parameters
           ILSCHUR

                     ILSCHUR is LOGICAL
                         Determines whether or not to update the full Schur form

           ILQ

                     ILQ is LOGICAL
                         Determines whether or not to update the matrix Q

           ILZ

                     ILZ is LOGICAL
                         Determines whether or not to update the matrix Z

           N

                     N is INTEGER
                     The order of the matrices A, B, Q, and Z.  N >= 0.

           ILO

                     ILO is INTEGER

           IHI

                     IHI is INTEGER
                     ILO and IHI mark the rows and columns of (A,B) which
                     are to be normalized

           NW

                     NW is INTEGER
                     The desired size of the deflation window.

           A

                     A is COMPLEX*16 array, dimension (LDA, N)

           LDA

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

           B

                     B is COMPLEX*16 array, dimension (LDB, N)

           LDB

                     LDB is INTEGER
                     The leading dimension of the array B.  LDB >= max( 1, N ).

           Q

                     Q is COMPLEX*16 array, dimension (LDQ, N)

           LDQ

                     LDQ is INTEGER

           Z

                     Z is COMPLEX*16 array, dimension (LDZ, N)

           LDZ

                     LDZ is INTEGER

           NS

                     NS is INTEGER
                     The number of unconverged eigenvalues available to
                     use as shifts.

           ND

                     ND is INTEGER
                     The number of converged eigenvalues found.

           ALPHA

                     ALPHA is COMPLEX*16 array, dimension (N)
                     Each scalar alpha defining an eigenvalue
                     of GNEP.

           BETA

                     BETA is COMPLEX*16 array, dimension (N)
                     The scalars beta that define the eigenvalues of GNEP.
                     Together, the quantities alpha = ALPHA(j) and
                     beta = BETA(j) represent the j-th eigenvalue of the matrix
                     pair (A,B), in one of the forms lambda = alpha/beta or
                     mu = beta/alpha.  Since either lambda or mu may overflow,
                     they should not, in general, be computed.

           QC

                     QC is COMPLEX*16 array, dimension (LDQC, NW)

           LDQC

                     LDQC is INTEGER

           ZC

                     ZC is COMPLEX*16 array, dimension (LDZC, NW)

           LDZC

                     LDZ is INTEGER

           WORK

                     WORK is COMPLEX*16 array, dimension (MAX(1,LWORK))
                     On exit, if INFO >= 0, WORK(1) returns the optimal LWORK.

           LWORK

                     LWORK is INTEGER
                     The dimension of the array WORK.  LWORK >= max(1,N).

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

           RWORK

                     RWORK is DOUBLE PRECISION array, dimension (N)

           REC

                     REC is INTEGER
                        REC indicates the current recursion level. Should be set
                        to 0 on first call.

           INFO

                     INFO is INTEGER
                     = 0: successful exit
                     < 0: if INFO = -i, the i-th argument had an illegal value

       Author
           Thijs Steel, KU Leuven

       Date
           May 2020

   subroutine zlaqz3 (logical, intent(in) ILSCHUR, logical, intent(in) ILQ, logical, intent(in)
       ILZ, integer, intent(in) N, integer, intent(in) ILO, integer, intent(in) IHI, integer,
       intent(in) NSHIFTS, integer, intent(in) NBLOCK_DESIRED, complex*16, dimension( * ),
       intent(inout) ALPHA, complex*16, dimension( * ), intent(inout) BETA, complex*16,
       dimension( lda, * ), intent(inout) A, integer, intent(in) LDA, complex*16, dimension( ldb,
       * ), intent(inout) B, integer, intent(in) LDB, complex*16, dimension( ldq,         * ),
       intent(inout) Q, integer, intent(in) LDQ, complex*16, dimension( ldz, * ), intent(inout)
       Z, integer, intent(in) LDZ, complex*16, dimension( ldqc, * ), intent(inout) QC, integer,
       intent(in) LDQC, complex*16, dimension( ldzc, * ), intent(inout) ZC, integer, intent(in)
       LDZC, complex*16, dimension( * ), intent(inout) WORK, integer, intent(in) LWORK, integer,
       intent(out) INFO)
       ZLAQZ3

       Purpose:

            ZLAQZ3 Executes a single multishift QZ sweep

       Parameters
           ILSCHUR

                     ILSCHUR is LOGICAL
                         Determines whether or not to update the full Schur form

           ILQ

                     ILQ is LOGICAL
                         Determines whether or not to update the matrix Q

           ILZ

                     ILZ is LOGICAL
                         Determines whether or not to update the matrix Z

           N

                     N is INTEGER
                     The order of the matrices A, B, Q, and Z.  N >= 0.

           ILO

                     ILO is INTEGER

           IHI

                     IHI is INTEGER

           NSHIFTS

                     NSHIFTS is INTEGER
                     The desired number of shifts to use

           NBLOCK_DESIRED

                     NBLOCK_DESIRED is INTEGER
                     The desired size of the computational windows

           ALPHA

                     ALPHA is COMPLEX*16 array. SR contains
                     the alpha parts of the shifts to use.

           BETA

                     BETA is COMPLEX*16 array. SS contains
                     the scale of the shifts to use.

           A

                     A is COMPLEX*16 array, dimension (LDA, N)

           LDA

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

           B

                     B is COMPLEX*16 array, dimension (LDB, N)

           LDB

                     LDB is INTEGER
                     The leading dimension of the array B.  LDB >= max( 1, N ).

           Q

                     Q is COMPLEX*16 array, dimension (LDQ, N)

           LDQ

                     LDQ is INTEGER

           Z

                     Z is COMPLEX*16 array, dimension (LDZ, N)

           LDZ

                     LDZ is INTEGER

           QC

                     QC is COMPLEX*16 array, dimension (LDQC, NBLOCK_DESIRED)

           LDQC

                     LDQC is INTEGER

           ZC

                     ZC is COMPLEX*16 array, dimension (LDZC, NBLOCK_DESIRED)

           LDZC

                     LDZ is INTEGER

           WORK

                     WORK is COMPLEX*16 array, dimension (MAX(1,LWORK))
                     On exit, if INFO >= 0, WORK(1) returns the optimal LWORK.

           LWORK

                     LWORK is INTEGER
                     The dimension of the array WORK.  LWORK >= max(1,N).

                     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.

           INFO

                     INFO is INTEGER
                     = 0: successful exit
                     < 0: if INFO = -i, the i-th argument had an illegal value

       Author
           Thijs Steel, KU Leuven

       Date
           May 2020

   subroutine zlaunhr_col_getrfnp (integer M, integer N, complex*16, dimension( lda, * ) A,
       integer LDA, complex*16, dimension( * ) D, integer INFO)
       ZLAUNHR_COL_GETRFNP

       Purpose:

            ZLAUNHR_COL_GETRFNP computes the modified LU factorization without
            pivoting of a complex general M-by-N matrix A. The factorization has
            the form:

                A - S = L * U,

            where:
               S is a m-by-n diagonal sign matrix with the diagonal D, so that
               D(i) = S(i,i), 1 <= i <= min(M,N). The diagonal D is constructed
               as D(i)=-SIGN(A(i,i)), where A(i,i) is the value after performing
               i-1 steps of Gaussian elimination. This means that the diagonal
               element at each step of 'modified' Gaussian elimination is
               at least one in absolute value (so that division-by-zero not
               not possible during the division by the diagonal element);

               L is a M-by-N lower triangular matrix with unit diagonal elements
               (lower trapezoidal if M > N);

               and U is a M-by-N upper triangular matrix
               (upper trapezoidal if M < N).

            This routine is an auxiliary routine used in the Householder
            reconstruction routine ZUNHR_COL. In ZUNHR_COL, this routine is
            applied to an M-by-N matrix A with orthonormal columns, where each
            element is bounded by one in absolute value. With the choice of
            the matrix S above, one can show that the diagonal element at each
            step of Gaussian elimination is the largest (in absolute value) in
            the column on or below the diagonal, so that no pivoting is required
            for numerical stability [1].

            For more details on the Householder reconstruction algorithm,
            including the modified LU factorization, see [1].

            This is the blocked right-looking version of the algorithm,
            calling Level 3 BLAS to update the submatrix. To factorize a block,
            this routine calls the recursive routine ZLAUNHR_COL_GETRFNP2.

            [1] 'Reconstructing Householder vectors from tall-skinny QR',
                G. Ballard, J. Demmel, L. Grigori, M. Jacquelin, H.D. Nguyen,
                E. Solomonik, J. Parallel Distrib. Comput.,
                vol. 85, pp. 3-31, 2015.

       Parameters
           M

                     M is INTEGER
                     The number of rows of the matrix A.  M >= 0.

           N

                     N is INTEGER
                     The number of columns of the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the M-by-N matrix to be factored.
                     On exit, the factors L and U from the factorization
                     A-S=L*U; the unit diagonal elements of L are not stored.

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,M).

           D

                     D is COMPLEX*16 array, dimension min(M,N)
                     The diagonal elements of the diagonal M-by-N sign matrix S,
                     D(i) = S(i,i), where 1 <= i <= min(M,N). The elements can be
                     only ( +1.0, 0.0 ) or (-1.0, 0.0 ).

           INFO

                     INFO is INTEGER
                     = 0:  successful exit
                     < 0:  if INFO = -i, the i-th argument had an illegal value

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Contributors:

            November 2019, Igor Kozachenko,
                           Computer Science Division,
                           University of California, Berkeley

   recursive subroutine zlaunhr_col_getrfnp2 (integer M, integer N, complex*16, dimension( lda, *
       ) A, integer LDA, complex*16, dimension( * ) D, integer INFO)
       ZLAUNHR_COL_GETRFNP2

       Purpose:

            ZLAUNHR_COL_GETRFNP2 computes the modified LU factorization without
            pivoting of a complex general M-by-N matrix A. The factorization has
            the form:

                A - S = L * U,

            where:
               S is a m-by-n diagonal sign matrix with the diagonal D, so that
               D(i) = S(i,i), 1 <= i <= min(M,N). The diagonal D is constructed
               as D(i)=-SIGN(A(i,i)), where A(i,i) is the value after performing
               i-1 steps of Gaussian elimination. This means that the diagonal
               element at each step of 'modified' Gaussian elimination is at
               least one in absolute value (so that division-by-zero not
               possible during the division by the diagonal element);

               L is a M-by-N lower triangular matrix with unit diagonal elements
               (lower trapezoidal if M > N);

               and U is a M-by-N upper triangular matrix
               (upper trapezoidal if M < N).

            This routine is an auxiliary routine used in the Householder
            reconstruction routine ZUNHR_COL. In ZUNHR_COL, this routine is
            applied to an M-by-N matrix A with orthonormal columns, where each
            element is bounded by one in absolute value. With the choice of
            the matrix S above, one can show that the diagonal element at each
            step of Gaussian elimination is the largest (in absolute value) in
            the column on or below the diagonal, so that no pivoting is required
            for numerical stability [1].

            For more details on the Householder reconstruction algorithm,
            including the modified LU factorization, see [1].

            This is the recursive version of the LU factorization algorithm.
            Denote A - S by B. The algorithm divides the matrix B into four
            submatrices:

                   [  B11 | B12  ]  where B11 is n1 by n1,
               B = [ -----|----- ]        B21 is (m-n1) by n1,
                   [  B21 | B22  ]        B12 is n1 by n2,
                                          B22 is (m-n1) by n2,
                                          with n1 = min(m,n)/2, n2 = n-n1.

            The subroutine calls itself to factor B11, solves for B21,
            solves for B12, updates B22, then calls itself to factor B22.

            For more details on the recursive LU algorithm, see [2].

            ZLAUNHR_COL_GETRFNP2 is called to factorize a block by the blocked
            routine ZLAUNHR_COL_GETRFNP, which uses blocked code calling
            Level 3 BLAS to update the submatrix. However, ZLAUNHR_COL_GETRFNP2
            is self-sufficient and can be used without ZLAUNHR_COL_GETRFNP.

            [1] 'Reconstructing Householder vectors from tall-skinny QR',
                G. Ballard, J. Demmel, L. Grigori, M. Jacquelin, H.D. Nguyen,
                E. Solomonik, J. Parallel Distrib. Comput.,
                vol. 85, pp. 3-31, 2015.

            [2] 'Recursion leads to automatic variable blocking for dense linear
                algebra algorithms', F. Gustavson, IBM J. of Res. and Dev.,
                vol. 41, no. 6, pp. 737-755, 1997.

       Parameters
           M

                     M is INTEGER
                     The number of rows of the matrix A.  M >= 0.

           N

                     N is INTEGER
                     The number of columns of the matrix A.  N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the M-by-N matrix to be factored.
                     On exit, the factors L and U from the factorization
                     A-S=L*U; the unit diagonal elements of L are not stored.

           LDA

                     LDA is INTEGER
                     The leading dimension of the array A.  LDA >= max(1,M).

           D

                     D is COMPLEX*16 array, dimension min(M,N)
                     The diagonal elements of the diagonal M-by-N sign matrix S,
                     D(i) = S(i,i), where 1 <= i <= min(M,N). The elements can be
                     only ( +1.0, 0.0 ) or (-1.0, 0.0 ).

           INFO

                     INFO is INTEGER
                     = 0:  successful exit
                     < 0:  if INFO = -i, the i-th argument had an illegal value

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Contributors:

            November 2019, Igor Kozachenko,
                           Computer Science Division,
                           University of California, Berkeley

   subroutine ztgevc (character SIDE, character HOWMNY, logical, dimension( * ) SELECT, integer
       N, complex*16, dimension( lds, * ) S, integer LDS, complex*16, dimension( ldp, * ) P,
       integer LDP, complex*16, dimension( ldvl, * ) VL, integer LDVL, complex*16, dimension(
       ldvr, * ) VR, integer LDVR, integer MM, integer M, complex*16, dimension( * ) WORK, double
       precision, dimension( * ) RWORK, integer INFO)
       ZTGEVC

       Purpose:

            ZTGEVC computes some or all of the right and/or left eigenvectors of
            a pair of complex matrices (S,P), where S and P are upper triangular.
            Matrix pairs of this type are produced by the generalized Schur
            factorization of a complex matrix pair (A,B):

               A = Q*S*Z**H,  B = Q*P*Z**H

            as computed by ZGGHRD + ZHGEQZ.

            The right eigenvector x and the left eigenvector y of (S,P)
            corresponding to an eigenvalue w are defined by:

               S*x = w*P*x,  (y**H)*S = w*(y**H)*P,

            where y**H denotes the conjugate tranpose of y.
            The eigenvalues are not input to this routine, but are computed
            directly from the diagonal elements of S and P.

            This routine returns the matrices X and/or Y of right and left
            eigenvectors of (S,P), or the products Z*X and/or Q*Y,
            where Z and Q are input matrices.
            If Q and Z are the unitary factors from the generalized Schur
            factorization of a matrix pair (A,B), then Z*X and Q*Y
            are the matrices of right and left eigenvectors of (A,B).

       Parameters
           SIDE

                     SIDE is CHARACTER*1
                     = 'R': compute right eigenvectors only;
                     = 'L': compute left eigenvectors only;
                     = 'B': compute both right and left eigenvectors.

           HOWMNY

                     HOWMNY is CHARACTER*1
                     = 'A': compute all right and/or left eigenvectors;
                     = 'B': compute all right and/or left eigenvectors,
                            backtransformed by the matrices in VR and/or VL;
                     = 'S': compute selected right and/or left eigenvectors,
                            specified by the logical array SELECT.

           SELECT

                     SELECT is LOGICAL array, dimension (N)
                     If HOWMNY='S', SELECT specifies the eigenvectors to be
                     computed.  The eigenvector corresponding to the j-th
                     eigenvalue is computed if SELECT(j) = .TRUE..
                     Not referenced if HOWMNY = 'A' or 'B'.

           N

                     N is INTEGER
                     The order of the matrices S and P.  N >= 0.

           S

                     S is COMPLEX*16 array, dimension (LDS,N)
                     The upper triangular matrix S from a generalized Schur
                     factorization, as computed by ZHGEQZ.

           LDS

                     LDS is INTEGER
                     The leading dimension of array S.  LDS >= max(1,N).

           P

                     P is COMPLEX*16 array, dimension (LDP,N)
                     The upper triangular matrix P from a generalized Schur
                     factorization, as computed by ZHGEQZ.  P must have real
                     diagonal elements.

           LDP

                     LDP is INTEGER
                     The leading dimension of array P.  LDP >= max(1,N).

           VL

                     VL is COMPLEX*16 array, dimension (LDVL,MM)
                     On entry, if SIDE = 'L' or 'B' and HOWMNY = 'B', VL must
                     contain an N-by-N matrix Q (usually the unitary matrix Q
                     of left Schur vectors returned by ZHGEQZ).
                     On exit, if SIDE = 'L' or 'B', VL contains:
                     if HOWMNY = 'A', the matrix Y of left eigenvectors of (S,P);
                     if HOWMNY = 'B', the matrix Q*Y;
                     if HOWMNY = 'S', the left eigenvectors of (S,P) specified by
                                 SELECT, stored consecutively in the columns of
                                 VL, in the same order as their eigenvalues.
                     Not referenced if SIDE = 'R'.

           LDVL

                     LDVL is INTEGER
                     The leading dimension of array VL.  LDVL >= 1, and if
                     SIDE = 'L' or 'l' or 'B' or 'b', LDVL >= N.

           VR

                     VR is COMPLEX*16 array, dimension (LDVR,MM)
                     On entry, if SIDE = 'R' or 'B' and HOWMNY = 'B', VR must
                     contain an N-by-N matrix Q (usually the unitary matrix Z
                     of right Schur vectors returned by ZHGEQZ).
                     On exit, if SIDE = 'R' or 'B', VR contains:
                     if HOWMNY = 'A', the matrix X of right eigenvectors of (S,P);
                     if HOWMNY = 'B', the matrix Z*X;
                     if HOWMNY = 'S', the right eigenvectors of (S,P) specified by
                                 SELECT, stored consecutively in the columns of
                                 VR, in the same order as their eigenvalues.
                     Not referenced if SIDE = 'L'.

           LDVR

                     LDVR is INTEGER
                     The leading dimension of the array VR.  LDVR >= 1, and if
                     SIDE = 'R' or 'B', LDVR >= N.

           MM

                     MM is INTEGER
                     The number of columns in the arrays VL and/or VR. MM >= M.

           M

                     M is INTEGER
                     The number of columns in the arrays VL and/or VR actually
                     used to store the eigenvectors.  If HOWMNY = 'A' or 'B', M
                     is set to N.  Each selected eigenvector occupies one column.

           WORK

                     WORK is COMPLEX*16 array, dimension (2*N)

           RWORK

                     RWORK is DOUBLE PRECISION array, dimension (2*N)

           INFO

                     INFO is INTEGER
                     = 0:  successful exit.
                     < 0:  if INFO = -i, the i-th argument had an illegal value.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

   subroutine ztgexc (logical WANTQ, logical WANTZ, integer N, complex*16, dimension( lda, * ) A,
       integer LDA, complex*16, dimension( ldb, * ) B, integer LDB, complex*16, dimension( ldq, *
       ) Q, integer LDQ, complex*16, dimension( ldz, * ) Z, integer LDZ, integer IFST, integer
       ILST, integer INFO)
       ZTGEXC

       Purpose:

            ZTGEXC reorders the generalized Schur decomposition of a complex
            matrix pair (A,B), using an unitary equivalence transformation
            (A, B) := Q * (A, B) * Z**H, so that the diagonal block of (A, B) with
            row index IFST is moved to row ILST.

            (A, B) must be in generalized Schur canonical form, that is, A and
            B are both upper triangular.

            Optionally, the matrices Q and Z of generalized Schur vectors are
            updated.

                   Q(in) * A(in) * Z(in)**H = Q(out) * A(out) * Z(out)**H
                   Q(in) * B(in) * Z(in)**H = Q(out) * B(out) * Z(out)**H

       Parameters
           WANTQ

                     WANTQ is LOGICAL
                     .TRUE. : update the left transformation matrix Q;
                     .FALSE.: do not update Q.

           WANTZ

                     WANTZ is LOGICAL
                     .TRUE. : update the right transformation matrix Z;
                     .FALSE.: do not update Z.

           N

                     N is INTEGER
                     The order of the matrices A and B. N >= 0.

           A

                     A is COMPLEX*16 array, dimension (LDA,N)
                     On entry, the upper triangular matrix A in the pair (A, B).
                     On exit, the updated matrix A.

           LDA

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

           B

                     B is COMPLEX*16 array, dimension (LDB,N)
                     On entry, the upper triangular matrix B in the pair (A, B).
                     On exit, the updated matrix B.

           LDB

                     LDB is INTEGER
                     The leading dimension of the array B. LDB >= max(1,N).

           Q

                     Q is COMPLEX*16 array, dimension (LDQ,N)
                     On entry, if WANTQ = .TRUE., the unitary matrix Q.
                     On exit, the updated matrix Q.
                     If WANTQ = .FALSE., Q is not referenced.

           LDQ

                     LDQ is INTEGER
                     The leading dimension of the array Q. LDQ >= 1;
                     If WANTQ = .TRUE., LDQ >= N.

           Z

                     Z is COMPLEX*16 array, dimension (LDZ,N)
                     On entry, if WANTZ = .TRUE., the unitary matrix Z.
                     On exit, the updated matrix Z.
                     If WANTZ = .FALSE., Z is not referenced.

           LDZ

                     LDZ is INTEGER
                     The leading dimension of the array Z. LDZ >= 1;
                     If WANTZ = .TRUE., LDZ >= N.

           IFST

                     IFST is INTEGER

           ILST

                     ILST is INTEGER
                     Specify the reordering of the diagonal blocks of (A, B).
                     The block with row index IFST is moved to row ILST, by a
                     sequence of swapping between adjacent blocks.

           INFO

                     INFO is INTEGER
                      =0:  Successful exit.
                      <0:  if INFO = -i, the i-th argument had an illegal value.
                      =1:  The transformed matrix pair (A, B) would be too far
                           from generalized Schur form; the problem is ill-
                           conditioned. (A, B) may have been partially reordered,
                           and ILST points to the first row of the current
                           position of the block being moved.

       Author
           Univ. of Tennessee

           Univ. of California Berkeley

           Univ. of Colorado Denver

           NAG Ltd.

       Contributors:
           Bo Kagstrom and Peter Poromaa, Department of Computing Science, Umea University, S-901
           87 Umea, Sweden.

       References:
           [1] B. Kagstrom; A Direct Method for Reordering Eigenvalues in the Generalized Real
           Schur Form of a Regular Matrix Pair (A, B), in M.S. Moonen et al (eds), Linear Algebra
           for Large Scale and Real-Time Applications, Kluwer Academic Publ. 1993, pp 195-218.
            [2] B. Kagstrom and P. Poromaa; Computing Eigenspaces with Specified Eigenvalues of a
           Regular Matrix Pair (A, B) and Condition Estimation: Theory, Algorithms and Software,
           Report UMINF - 94.04, Department of Computing Science, Umea University, S-901 87 Umea,
           Sweden, 1994. Also as LAPACK Working Note 87. To appear in Numerical Algorithms, 1996.
            [3] B. Kagstrom and P. Poromaa, LAPACK-Style Algorithms and Software for Solving the
           Generalized Sylvester Equation and Estimating the Separation between Regular Matrix
           Pairs, Report UMINF - 93.23, Department of Computing Science, Umea University, S-901
           87 Umea, Sweden, December 1993, Revised April 1994, Also as LAPACK working Note 75. To
           appear in ACM Trans. on Math. Software, Vol 22, No 1, 1996.

Author

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