Provided by: liblapack-doc_3.3.1-1_all
LAPACK-3 - generates an m by n real matrix Q with orthonormal rows,
SUBROUTINE SORGR2( M, N, K, A, LDA, TAU, WORK, INFO ) INTEGER INFO, K, LDA, M, N REAL A( LDA, * ), TAU( * ), WORK( * )
SORGR2 generates an m by n real matrix Q with orthonormal rows, which is defined as the last m rows of a product of k elementary reflectors of order n Q = H(1) H(2) . . . H(k) as returned by SGERQF.
M (input) INTEGER The number of rows of the matrix Q. M >= 0. N (input) INTEGER The number of columns of the matrix Q. N >= M. K (input) INTEGER The number of elementary reflectors whose product defines the matrix Q. M >= K >= 0. A (input/output) REAL array, dimension (LDA,N) On entry, the (m-k+i)-th row must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by SGERQF in the last k rows 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 SGERQF. WORK (workspace) REAL array, dimension (M) INFO (output) INTEGER = 0: successful exit < 0: if INFO = -i, the i-th argument has an illegal value LAPACK routine (version 3.2) April 2011 SORGR2(3lapack)