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DORG2L(1) LAPACK routine (version 3.2) DORG2L(1)

NAME

DORG2L - generates an m by n real matrix Q with orthonormal columns,

SYNOPSIS

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 m
Q = H(k) . . . H(2) H(1)
as returned by DGEQLF.

ARGUMENTS

The number of rows of the matrix Q. M >= 0.
The number of columns of the matrix Q. M >= N >= 0.
The number of elementary reflectors whose product defines the matrix Q. N >= K >= 0.
On entry, the (n-k+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.
The first dimension of the array A. LDA >= max(1,M).
TAU(i) must contain the scalar factor of the elementary reflector H(i), as returned by DGEQLF.
= 0: successful exit
< 0: if INFO = -i, the i-th argument has an illegal value
November 2008 LAPACK routine (version 3.2)