PLASMA  2.8.0
PLASMA - Parallel Linear Algebra for Scalable Multi-core Architectures
int PLASMA_zgebrd ( PLASMA_enum  jobq,
PLASMA_enum  jobp,
int  M,
int  N,
PLASMA_Complex64_t *  A,
int  LDA,
double *  D,
double *  E,
PLASMA_desc descT,
PLASMA_Complex64_t *  Q,
int  LDQ,
PLASMA_Complex64_t *  P,
int  LDP 
)

PLASMA_zgebrd - reduces a general complex M-by-N matrix A to upper or lower bidiagonal form B using a two-stage approach First stage: reduction to band bidiagonal form (orthogonal matrices Q1 and P1); Second stage: reduction from band to bidiagonal form (orthogonal matrices Q2 and P2). Let Q = Q1 * Q2 be the global left unitary transformation; Let P = P1 * P2 be the global right unitary transformation; Q**H * A * P = B. If M >= N, B is upper bidiagonal; if M < N, B is lower bidiagonal. Not LAPACK Compliant for now! Note: T is incomplete and contains only the block reflectors of the first stage. Therefore, Q and P can not be built completely.

Parameters
[in]jobqSpecifies options for computing all or part of the matrix Q. Intended usage: = PlasmaVec: all M columns of Q are returned in array Q; = PlasmaNoVec: not referenced.
[in]jobpSpecifies options for computing all or part of the matrix V**H. Intended usage: = PlasmaVec: all N columns of P are returned in array P; = PlasmaNoVec: not referenced.
[in]MThe number of rows of the matrix A. M >= 0.
[in]NThe number of columns of the matrix A. N >= 0.
[in,out]AOn entry, the M-by-N matrix A. 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 T, represent the unitary matrix Q as a product of elementary reflectors, and the elements above the first superdiagonal, with the array T, 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 T, represent the unitary matrix Q as a product of elementary reflectors, and the elements above the diagonal, with the array T, represent the unitary matrix P as a product of elementary reflectors.
[in]LDAThe leading dimension of the array A. LDA >= max(1,M).
[out]DOn exit, the diagonal elements of the bidiagonal matrix: D(i) = A(i,i). Dimension (min(M,N)).
[out]EOn exit, the off-diagonal elements of the bidiagonal matrix: 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. Dimension (min(M,N)-1).
[out]descTOn entry, descriptor as return by PLASMA_Alloc_Workspace_zgebrd On exit, contains auxiliary factorization data.
[out]QOn exit, if jobz = PlasmaVec, then if return value = 0, Q contains the M-by-M unitary matrix Q. If jobz = PlasmaNoVec, then it is not referenced.
[in]LDQThe leading dimension of the array Q. LDQ >= M.
[out]POn exit, if jobz = PlasmaVec, then if return value = 0, P contains the N-by-N unitary matrix P. If jobz = PlasmaNoVec, then it is not referenced.
[in]LDPThe leading dimension of the array P. LDP >= N.
Returns
Return values
PLASMA_SUCCESSsuccessful exit
<0if -i, the i-th argument had an illegal value
See also
PLASMA_zgebrd_Tile
PLASMA_zgebrd_Tile_Async
PLASMA_cgebrd
PLASMA_dgebrd
PLASMA_sgebrd