PLASMA  2.8.0
PLASMA - Parallel Linear Algebra for Scalable Multi-core Architectures
int CORE_zgeqrt ( int  M,
int  N,
int  IB,
PLASMA_Complex64_t *  A,
int  LDA,
PLASMA_Complex64_t *  T,
int  LDT,
PLASMA_Complex64_t *  TAU,
PLASMA_Complex64_t *  WORK 
)

CORE_zgeqrt computes a QR factorization of a complex M-by-N tile A: A = Q * R.

The tile 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'

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).

Parameters
[in]MThe number of rows of the tile A. M >= 0.
[in]NThe number of columns of the tile A. N >= 0.
[in]IBThe inner-blocking size. IB >= 0.
[in,out]AOn entry, the M-by-N tile A. On exit, the elements on and above the diagonal of the array contain the min(M,N)-by-N upper trapezoidal tile R (R is upper triangular if M >= N); the elements below the diagonal, with the array TAU, represent the unitary tile Q as a product of elementary reflectors (see Further Details).
[in]LDAThe leading dimension of the array A. LDA >= max(1,M).
[out]TThe IB-by-N triangular factor T of the block reflector. T is upper triangular by block (economic storage); The rest of the array is not referenced.
[in]LDTThe leading dimension of the array T. LDT >= IB.
[out]TAUThe scalar factors of the elementary reflectors (see Further Details).
[out]WORK
Returns
Return values
PLASMA_SUCCESSsuccessful exit
<0if -i, the i-th argument had an illegal value