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template<typename T>
void geqlf(integer *m, integer *n, T *a, integer *lda, T *tau, T *work, integer *lwork, integer *info)# GEQLF computes a QL factorization of M-by-N matrix.
Purpose:
GEQLF computes a QL factorization of M-by-N matrix A: A = Q * L.
- Parameters:
M – [in]
M is INTEGER
The number of rows of the matrix A. M >= 0.
N – [in]
N is INTEGER
The number of columns of the matrix A. N >= 0.
A – [inout]
A is REAL 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 orthogonal matrix Q as a product of elementary reflectors (see Further Details).LDA – [in]
LDA is INTEGER
The leading dimension of the array A. LDA >= fla_max(1,M).
TAU – [out] TAU is array, dimension (min(M,N))
WORK – [out]
WORK is COMPLEX array, dimension (MAX(1,LWORK))
On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
LWORK – [in]
LWORK is INTEGER
The dimension of the array WORK. LWORK >= fla_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 – [out]
INFO is INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument had an illegal value