dorgl2(3F)

NAME
     DORGL2 - generate 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 n

           Q  =  H(k) . . . H(2) H(1)

     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 i-th 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
             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 DGELQF.

     WORK    (workspace) DOUBLE PRECISION array, dimension (M)

     INFO    (output) INTEGER
             = 0: successful exit
             < 0: if INFO = -i, the i-th argument has an illegal value