SRC/cgelq2.f(3)            Library Functions Manual            SRC/cgelq2.f(3)

NAME
       SRC/cgelq2.f

SYNOPSIS
   Functions/Subroutines
       subroutine cgelq2 (m, n, a, lda, tau, work, info)
           CGELQ2 computes the LQ factorization of a general rectangular
           matrix using an unblocked algorithm.

Function/Subroutine Documentation
   subroutine cgelq2 (integer m, integer n, complex, dimension( lda, * ) a,
       integer lda, complex, dimension( * ) tau, complex, dimension( * ) work,
       integer info)
       CGELQ2 computes the LQ factorization of a general rectangular matrix
       using an unblocked algorithm.

       Purpose:


           !>
           !> CGELQ2 computes an LQ factorization of a complex m-by-n matrix A:
           !>
           !>    A = ( L 0 ) *  Q
           !>
           !> where:
           !>
           !>    Q is a n-by-n orthogonal matrix;
           !>    L is a lower-triangular m-by-m matrix;
           !>    0 is a m-by-(n-m) zero matrix, if m < n.
           !>
           !>

       Parameters
           M

           !>          M is INTEGER
           !>          The number of rows of the matrix A.  M >= 0.
           !>

           N

           !>          N is INTEGER
           !>          The number of columns of the matrix A.  N >= 0.
           !>

           A

           !>          A is COMPLEX array, dimension (LDA,N)
           !>          On entry, the m by n matrix A.
           !>          On exit, the elements on and below the diagonal of the array
           !>          contain the m by min(m,n) lower trapezoidal matrix L (L is
           !>          lower triangular if m <= n); the elements above the diagonal,
           !>          with the array TAU, represent the unitary matrix Q as a
           !>          product of elementary reflectors (see Further Details).
           !>

           LDA

           !>          LDA is INTEGER
           !>          The leading dimension of the array A.  LDA >= max(1,M).
           !>

           TAU

           !>          TAU is COMPLEX array, dimension (min(M,N))
           !>          The scalar factors of the elementary reflectors (see Further
           !>          Details).
           !>

           WORK

           !>          WORK is COMPLEX array, dimension (M)
           !>

           INFO

           !>          INFO is INTEGER
           !>          = 0: successful exit
           !>          < 0: if INFO = -i, the i-th argument had an illegal value
           !>

       Author
           Univ. of Tennessee


           Univ. of California Berkeley


           Univ. of Colorado Denver


           NAG Ltd.

       Further Details:


           !>
           !>  The matrix Q is represented as a product of elementary reflectors
           !>
           !>     Q = H(k)**H . . . H(2)**H H(1)**H, where k = min(m,n).
           !>
           !>  Each H(i) has the form
           !>
           !>     H(i) = I - tau * v * v**H
           !>
           !>  where tau is a complex scalar, and v is a complex vector with
           !>  v(1:i-1) = 0 and v(i) = 1; conjg(v(i+1:n)) is stored on exit in
           !>  A(i,i+1:n), and tau in TAU(i).
           !>

       Definition at line 128 of file cgelq2.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

LAPACK                          Version 3.12.0                 SRC/cgelq2.f(3)