SRC/DEPRECATED/sgeqpf.f(3)                            Library Functions Manual

NAME
       SRC/DEPRECATED/sgeqpf.f

SYNOPSIS
   Functions/Subroutines
       subroutine sgeqpf (m, n, a, lda, jpvt, tau, work, info)
           SGEQPF

Function/Subroutine Documentation
   subroutine sgeqpf (integer m, integer n, real, dimension( lda, * ) a,
       integer lda, integer, dimension( * ) jpvt, real, dimension( * ) tau,
       real, dimension( * ) work, integer info)
       SGEQPF

       Purpose:


           !>
           !> This routine is deprecated and has been replaced by routine SGEQP3.
           !>
           !> SGEQPF computes a QR factorization with column pivoting of a
           !> real M-by-N matrix A: A*P = Q*R.
           !>

       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 REAL array, dimension (LDA,N)
           !>          On entry, the M-by-N matrix A.
           !>          On exit, the upper triangle of the array contains the
           !>          min(M,N)-by-N upper triangular matrix R; the elements
           !>          below the diagonal, together with the array TAU,
           !>          represent the orthogonal matrix Q as a product of
           !>          min(m,n) elementary reflectors.
           !>

           LDA

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

           JPVT

           !>          JPVT is INTEGER array, dimension (N)
           !>          On entry, if JPVT(i) .ne. 0, the i-th column of A is permuted
           !>          to the front of A*P (a leading column); if JPVT(i) = 0,
           !>          the i-th column of A is a free column.
           !>          On exit, if JPVT(i) = k, then the i-th column of A*P
           !>          was the k-th column of A.
           !>

           TAU

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

           WORK

           !>          WORK is REAL array, dimension (3*N)
           !>

           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(1) H(2) . . . H(n)
           !>
           !>  Each H(i) has the form
           !>
           !>     H = I - tau * v * v**T
           !>
           !>  where tau is a real scalar, and v is a real vector with
           !>  v(1:i-1) = 0 and v(i) = 1; v(i+1:m) is stored on exit in A(i+1:m,i).
           !>
           !>  The matrix P is represented in jpvt as follows: If
           !>     jpvt(j) = i
           !>  then the jth column of P is the ith canonical unit vector.
           !>
           !>  Partial column norm updating strategy modified by
           !>    Z. Drmac and Z. Bujanovic, Dept. of Mathematics,
           !>    University of Zagreb, Croatia.
           !>  -- April 2011                                                      --
           !>  For more details see LAPACK Working Note 176.
           !>

       Definition at line 141 of file sgeqpf.f.

Author
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LAPACK                          Version 3.12.0      SRC/DEPRECATED/sgeqpf.f(3)