Subroutine */
| 654 | } /* zgebal_ */ |
| 655 | |
| 656 | /* Subroutine */ int zgebd2_(integer *m, integer *n, doublecomplex *a, |
| 657 | integer *lda, doublereal *d__, doublereal *e, doublecomplex *tauq, |
| 658 | doublecomplex *taup, doublecomplex *work, integer *info) |
| 659 | { |
| 660 | /* System generated locals */ |
| 661 | integer a_dim1, a_offset, i__1, i__2, i__3; |
| 662 | doublecomplex z__1; |
| 663 | |
| 664 | /* Local variables */ |
| 665 | static integer i__; |
| 666 | static doublecomplex alpha; |
| 667 | extern /* Subroutine */ int zlarf_(char *, integer *, integer *, |
| 668 | doublecomplex *, integer *, doublecomplex *, doublecomplex *, |
| 669 | integer *, doublecomplex *), xerbla_(char *, integer *), zlarfg_(integer *, doublecomplex *, doublecomplex *, |
| 670 | integer *, doublecomplex *), zlacgv_(integer *, doublecomplex *, |
| 671 | integer *); |
| 672 | |
| 673 | |
| 674 | /* |
| 675 | -- LAPACK routine (version 3.2) -- |
| 676 | -- LAPACK is a software package provided by Univ. of Tennessee, -- |
| 677 | -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- |
| 678 | November 2006 |
| 679 | |
| 680 | |
| 681 | Purpose |
| 682 | ======= |
| 683 | |
| 684 | ZGEBD2 reduces a complex general m by n matrix A to upper or lower |
| 685 | real bidiagonal form B by a unitary transformation: Q' * A * P = B. |
| 686 | |
| 687 | If m >= n, B is upper bidiagonal; if m < n, B is lower bidiagonal. |
| 688 | |
| 689 | Arguments |
| 690 | ========= |
| 691 | |
| 692 | M (input) INTEGER |
| 693 | The number of rows in the matrix A. M >= 0. |
| 694 | |
| 695 | N (input) INTEGER |
| 696 | The number of columns in the matrix A. N >= 0. |
| 697 | |
| 698 | A (input/output) COMPLEX*16 array, dimension (LDA,N) |
| 699 | On entry, the m by n general matrix to be reduced. |
| 700 | On exit, |
| 701 | if m >= n, the diagonal and the first superdiagonal are |
| 702 | overwritten with the upper bidiagonal matrix B; the |
| 703 | elements below the diagonal, with the array TAUQ, represent |
| 704 | the unitary matrix Q as a product of elementary |
| 705 | reflectors, and the elements above the first superdiagonal, |
| 706 | with the array TAUP, represent the unitary matrix P as |
| 707 | a product of elementary reflectors; |
| 708 | if m < n, the diagonal and the first subdiagonal are |
| 709 | overwritten with the lower bidiagonal matrix B; the |
| 710 | elements below the first subdiagonal, with the array TAUQ, |
| 711 | represent the unitary matrix Q as a product of |
| 712 | elementary reflectors, and the elements above the diagonal, |
| 713 | with the array TAUP, represent the unitary matrix P as |