dorgl2 (l)  Linux Man Pages
dorgl2: generates an m by n real matrix Q with orthonormal rows,
NAME
DORGL2  generates an m by n real matrix Q with orthonormal rows,SYNOPSIS
 SUBROUTINE DORGL2(
 M, N, K, A, LDA, TAU, WORK, INFO )
 INTEGER INFO, K, LDA, M, N
 DOUBLE PRECISION A( LDA, * ), TAU( * ), WORK( * )
PURPOSE
DORGL2 generates an m by n real matrix Q with orthonormal rows, which is defined as the first m rows of a product of k elementary reflectors of order nQ
as returned by DGELQF.
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. N >= M.
 K (input) INTEGER
 The number of elementary reflectors whose product defines the matrix Q. M >= K >= 0.
 A (input/output) DOUBLE PRECISION array, dimension (LDA,N)
 On entry, the ith row must contain the vector which defines the elementary reflector H(i), for i = 1,2,...,k, as returned by DGELQF in the first k rows of its array argument A. On exit, the mbyn 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 DGELQF.
 WORK (workspace) DOUBLE PRECISION array, dimension (M)
 INFO (output) INTEGER

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