Provided by: liblapack-doc_3.3.1-1_all bug

NAME

       LAPACK-3 - generates an M-by-N real matrix Q with orthonormal rows,

SYNOPSIS

       SUBROUTINE DORGRQ( M, N, K, A, LDA, TAU, WORK, LWORK, INFO )

           INTEGER        INFO, K, LDA, LWORK, M, N

           DOUBLE         PRECISION A( LDA, * ), TAU( * ), WORK( * )

PURPOSE

       DORGRQ generates an M-by-N real matrix Q with orthonormal rows,
        which is defined as the last M rows of a product of K elementary
        reflectors of order N
              Q  =  H(1) H(2) . . . H(k)
        as returned by DGERQF.

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 (m-k+i)-th row must contain the vector which
                defines the elementary reflector H(i), for i = 1,2,...,k, as
                returned by DGERQF in the last 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 DGERQF.

        WORK    (workspace/output) DOUBLE PRECISION array, dimension (MAX(1,LWORK))
                On exit, if INFO = 0, WORK(1) returns the optimal LWORK.

        LWORK   (input) INTEGER
                The dimension of the array WORK. LWORK >= max(1,M).
                For optimum performance LWORK >= M*NB, where NB is the
                optimal blocksize.
                If LWORK = -1, then a workspace query is assumed; the routine
                only calculates the optimal size of the WORK array, returns
                this value as the first entry of the WORK array, and no error
                message related to LWORK is issued by XERBLA.

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

 LAPACK routine (version 3.3.1)             April 2011                            DORGRQ(3lapack)