SORG2L(l) ) SORG2L(l)
SORG2L - generate an m by n real matrix Q with orthonormal columns,
SUBROUTINE SORG2L( M, N, K, A, LDA, TAU, WORK, INFO )
INTEGER INFO, K, LDA, M, N
REAL A( LDA, * ), TAU( * ), WORK( * )
SORG2L generates an m by n real matrix Q with orthonormal columns, which is defined as the
last n columns of a product of k elementary reflectors of order m
Q = H(k) . . . H(2) H(1)
as returned by SGEQLF.
M (input) INTEGER
The number of rows of the matrix Q. M >= 0.
N (input) INTEGER
The number of columns of the matrix Q. M >= N >= 0.
K (input) INTEGER
The number of elementary reflectors whose product defines the matrix Q. N >= K >=
A (input/output) REAL array, dimension (LDA,N)
On entry, the (n-k+i)-th column must contain the vector which defines the elemen-
tary reflector H(i), for i = 1,2,...,k, as returned by SGEQLF in the last k col-
umns of its array argument A. On exit, the m by n matrix Q.
LDA (input) INTEGER
The first dimension of the array A. LDA >= max(1,M).
TAU (input) REAL array, dimension (K)
TAU(i) must contain the scalar factor of the elementary reflector H(i), as
returned by SGEQLF.
WORK (workspace) REAL array, dimension (N)
INFO (output) INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument has an illegal value
LAPACK version 3.0 15 June 2000 SORG2L(l)