Contents
zunglq - generate an M-by-N complex matrix Q with orthonor-
mal rows,
SUBROUTINE ZUNGLQ(M, N, K, A, LDA, TAU, WORK, LWORK, INFO)
DOUBLE COMPLEX A(LDA,*), TAU(*), WORK(*)
INTEGER M, N, K, LDA, LWORK, INFO
SUBROUTINE ZUNGLQ_64(M, N, K, A, LDA, TAU, WORK, LWORK, INFO)
DOUBLE COMPLEX A(LDA,*), TAU(*), WORK(*)
INTEGER*8 M, N, K, LDA, LWORK, INFO
F95 INTERFACE
SUBROUTINE UNGLQ(M, [N], [K], A, [LDA], TAU, [WORK], [LWORK], [INFO])
COMPLEX(8), DIMENSION(:) :: TAU, WORK
COMPLEX(8), DIMENSION(:,:) :: A
INTEGER :: M, N, K, LDA, LWORK, INFO
SUBROUTINE UNGLQ_64(M, [N], [K], A, [LDA], TAU, [WORK], [LWORK],
[INFO])
COMPLEX(8), DIMENSION(:) :: TAU, WORK
COMPLEX(8), DIMENSION(:,:) :: A
INTEGER(8) :: M, N, K, LDA, LWORK, INFO
C INTERFACE
#include <sunperf.h>
void zunglq(int m, int n, int k, doublecomplex *a, int lda,
doublecomplex *tau, int *info);
void zunglq_64(long m, long n, long k, doublecomplex *a,
long lda, doublecomplex *tau, long *info);
zunglq generates an M-by-N complex matrix Q with orthonormal
rows, which is defined as the first M rows of a product of K
elementary reflectors of order N
Q = H(k)' . . . H(2)' H(1)'
as returned by CGELQF.
M (input) The number of rows of the matrix Q. M >= 0.
N (input) The number of columns of the matrix Q. N >= M.
K (input) The number of elementary reflectors whose product
defines the matrix Q. M >= K >= 0.
A (input/output)
On entry, the i-th row must contain the vector
which defines the elementary reflector H(i), for i
= 1,2,...,k, as returned by CGELQF in the first k
rows of its array argument A. On exit, the M-by-N
matrix Q.
LDA (input)
The first dimension of the array A. LDA >=
max(1,M).
TAU (input)
TAU(i) must contain the scalar factor of the ele-
mentary reflector H(i), as returned by CGELQF.
WORK (workspace)
On exit, if INFO = 0, WORK(1) returns the optimal
LWORK.
LWORK (input)
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 (output)
= 0: successful exit;
< 0: if INFO = -i, the i-th argument has an ille-
gal value