```      SUBROUTINE DGEQPF( M, N, A, LDA, JPVT, TAU, WORK, INFO )
*
*  -- LAPACK deprecated driver routine (version 3.1) --
*     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
*     November 2006
*
*     .. Scalar Arguments ..
INTEGER            INFO, LDA, M, N
*     ..
*     .. Array Arguments ..
INTEGER            JPVT( * )
DOUBLE PRECISION   A( LDA, * ), TAU( * ), WORK( * )
*     ..
*
*  Purpose
*  =======
*
*  This routine is deprecated and has been replaced by routine DGEQP3.
*
*  DGEQPF computes a QR factorization with column pivoting of a
*  real M-by-N matrix A: A*P = Q*R.
*
*  Arguments
*  =========
*
*  M       (input) INTEGER
*          The number of rows of the matrix A. M >= 0.
*
*  N       (input) INTEGER
*          The number of columns of the matrix A. N >= 0
*
*  A       (input/output) DOUBLE PRECISION 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     (input) INTEGER
*          The leading dimension of the array A. LDA >= max(1,M).
*
*  JPVT    (input/output) 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     (output) DOUBLE PRECISION array, dimension (min(M,N))
*          The scalar factors of the elementary reflectors.
*
*  WORK    (workspace) DOUBLE PRECISION array, dimension (3*N)
*
*  INFO    (output) INTEGER
*          = 0:  successful exit
*          < 0:  if INFO = -i, the i-th argument had an illegal value
*
*  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'
*
*  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.
*    June 2006.
*  For more details see LAPACK Working Note 176.
*
*  =====================================================================
*
*     .. Parameters ..
DOUBLE PRECISION   ZERO, ONE
PARAMETER          ( ZERO = 0.0D+0, ONE = 1.0D+0 )
*     ..
*     .. Local Scalars ..
INTEGER            I, ITEMP, J, MA, MN, PVT
DOUBLE PRECISION   AII, TEMP, TEMP2, TOL3Z
*     ..
*     .. External Subroutines ..
EXTERNAL           DGEQR2, DLARF, DLARFG, DORM2R, DSWAP, XERBLA
*     ..
*     .. Intrinsic Functions ..
INTRINSIC          ABS, MAX, MIN, SQRT
*     ..
*     .. External Functions ..
INTEGER            IDAMAX
DOUBLE PRECISION   DLAMCH, DNRM2
EXTERNAL           IDAMAX, DLAMCH, DNRM2
*     ..
*     .. Executable Statements ..
*
*     Test the input arguments
*
INFO = 0
IF( M.LT.0 ) THEN
INFO = -1
ELSE IF( N.LT.0 ) THEN
INFO = -2
ELSE IF( LDA.LT.MAX( 1, M ) ) THEN
INFO = -4
END IF
IF( INFO.NE.0 ) THEN
CALL XERBLA( 'DGEQPF', -INFO )
RETURN
END IF
*
MN = MIN( M, N )
TOL3Z = SQRT(DLAMCH('Epsilon'))
*
*     Move initial columns up front
*
ITEMP = 1
DO 10 I = 1, N
IF( JPVT( I ).NE.0 ) THEN
IF( I.NE.ITEMP ) THEN
CALL DSWAP( M, A( 1, I ), 1, A( 1, ITEMP ), 1 )
JPVT( I ) = JPVT( ITEMP )
JPVT( ITEMP ) = I
ELSE
JPVT( I ) = I
END IF
ITEMP = ITEMP + 1
ELSE
JPVT( I ) = I
END IF
10 CONTINUE
ITEMP = ITEMP - 1
*
*     Compute the QR factorization and update remaining columns
*
IF( ITEMP.GT.0 ) THEN
MA = MIN( ITEMP, M )
CALL DGEQR2( M, MA, A, LDA, TAU, WORK, INFO )
IF( MA.LT.N ) THEN
CALL DORM2R( 'Left', 'Transpose', M, N-MA, MA, A, LDA, TAU,
\$                   A( 1, MA+1 ), LDA, WORK, INFO )
END IF
END IF
*
IF( ITEMP.LT.MN ) THEN
*
*        Initialize partial column norms. The first n elements of
*        work store the exact column norms.
*
DO 20 I = ITEMP + 1, N
WORK( I ) = DNRM2( M-ITEMP, A( ITEMP+1, I ), 1 )
WORK( N+I ) = WORK( I )
20    CONTINUE
*
*        Compute factorization
*
DO 40 I = ITEMP + 1, MN
*
*           Determine ith pivot column and swap if necessary
*
PVT = ( I-1 ) + IDAMAX( N-I+1, WORK( I ), 1 )
*
IF( PVT.NE.I ) THEN
CALL DSWAP( M, A( 1, PVT ), 1, A( 1, I ), 1 )
ITEMP = JPVT( PVT )
JPVT( PVT ) = JPVT( I )
JPVT( I ) = ITEMP
WORK( PVT ) = WORK( I )
WORK( N+PVT ) = WORK( N+I )
END IF
*
*           Generate elementary reflector H(i)
*
IF( I.LT.M ) THEN
CALL DLARFG( M-I+1, A( I, I ), A( I+1, I ), 1, TAU( I ) )
ELSE
CALL DLARFG( 1, A( M, M ), A( M, M ), 1, TAU( M ) )
END IF
*
IF( I.LT.N ) THEN
*
*              Apply H(i) to A(i:m,i+1:n) from the left
*
AII = A( I, I )
A( I, I ) = ONE
CALL DLARF( 'LEFT', M-I+1, N-I, A( I, I ), 1, TAU( I ),
\$                     A( I, I+1 ), LDA, WORK( 2*N+1 ) )
A( I, I ) = AII
END IF
*
*           Update partial column norms
*
DO 30 J = I + 1, N
IF( WORK( J ).NE.ZERO ) THEN
*
*                 NOTE: The following 4 lines follow from the analysis in
*                 Lapack Working Note 176.
*
TEMP = ABS( A( I, J ) ) / WORK( J )
TEMP = MAX( ZERO, ( ONE+TEMP )*( ONE-TEMP ) )
TEMP2 = TEMP*( WORK( J ) / WORK( N+J ) )**2
IF( TEMP2 .LE. TOL3Z ) THEN
IF( M-I.GT.0 ) THEN
WORK( J ) = DNRM2( M-I, A( I+1, J ), 1 )
WORK( N+J ) = WORK( J )
ELSE
WORK( J ) = ZERO
WORK( N+J ) = ZERO
END IF
ELSE
WORK( J ) = WORK( J )*SQRT( TEMP )
END IF
END IF
30       CONTINUE
*
40    CONTINUE
END IF
RETURN
*
*     End of DGEQPF
*
END

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