dorg2l (l)  Linux Man Pages
dorg2l: generates an m by n real matrix Q with orthonormal columns,
NAME
DORG2L  generates an m by n real matrix Q with orthonormal columns,SYNOPSIS
 SUBROUTINE DORG2L(
 M, N, K, A, LDA, TAU, WORK, INFO )
 INTEGER INFO, K, LDA, M, N
 DOUBLE PRECISION A( LDA, * ), TAU( * ), WORK( * )
PURPOSE
DORG2L 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 mQ
as returned by DGEQLF.
ARGUMENTS
 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 >= 0.
 A (input/output) DOUBLE PRECISION array, dimension (LDA,N)
 On entry, the (nk+i)th column must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by DGEQLF in the last k columns 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) DOUBLE PRECISION array, dimension (K)
 TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by DGEQLF.
 WORK (workspace) DOUBLE PRECISION array, dimension (N)
 INFO (output) INTEGER

= 0: successful exit
< 0: if INFO = i, the ith argument has an illegal value