sorgl2(3)

NAME

SORGL2 - generate an m by n real matrix Q with orthonormal

rows,

SYNOPSIS

SUBROUTINE SORGL2( M, N, K, A, LDA, TAU, WORK, INFO )
    INTEGER        INFO, K, LDA, M, N
    REAL           A( LDA, * ), TAU( * ), WORK( * )

PURPOSE

SORGL2 generates an m by n real matrix Q with orthonormal

rows, which is defined as the first m rows of a product of k ele

mentary reflectors of order n

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

as returned by SGELQF.

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) REAL 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 SGELQF 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) REAL array, dimension (K)

TAU(i) must contain the scalar factor of the ele

mentary reflector H(i), as returned by SGELQF.

WORK (workspace) REAL array, dimension (M)

INFO (output) INTEGER

= 0: successful exit
< 0: if INFO = -i, the i-th argument has an ille

gal value

LAPACK version 3.0 15 June 2000

SORGL2(3)