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dgsvj0.f(3)				      LAPACK				      dgsvj0.f(3)

NAME
       dgsvj0.f -

SYNOPSIS
   Functions/Subroutines
       subroutine dgsvj0 (JOBV, M, N, A, LDA, D, SVA, MV, V, LDV, EPS, SFMIN, TOL, NSWEEP, WORK,
	   LWORK, INFO)
	   DGSVJ0 pre-processor for the routine sgesvj.

Function/Subroutine Documentation
   subroutine dgsvj0 (character*1JOBV, integerM, integerN, double precision, dimension( lda, *
       )A, integerLDA, double precision, dimension( n )D, double precision, dimension( n )SVA,
       integerMV, double precision, dimension( ldv, * )V, integerLDV, double precisionEPS, double
       precisionSFMIN, double precisionTOL, integerNSWEEP, double precision, dimension( lwork
       )WORK, integerLWORK, integerINFO)
       DGSVJ0 pre-processor for the routine sgesvj.

       Purpose:

	    DGSVJ0 is called from DGESVJ as a pre-processor and that is its main
	    purpose. It applies Jacobi rotations in the same way as DGESVJ does, but
	    it does not check convergence (stopping criterion). Few tuning
	    parameters (marked by [TP]) are available for the implementer.

       Parameters:
	   JOBV

		     JOBV is CHARACTER*1
		     Specifies whether the output from this procedure is used
		     to compute the matrix V:
		     = 'V': the product of the Jacobi rotations is accumulated
			    by postmulyiplying the N-by-N array V.
			   (See the description of V.)
		     = 'A': the product of the Jacobi rotations is accumulated
			    by postmulyiplying the MV-by-N array V.
			   (See the descriptions of MV and V.)
		     = 'N': the Jacobi rotations are not accumulated.

	   M

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

	   N

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

	   A

		     A is DOUBLE PRECISION array, dimension (LDA,N)
		     On entry, M-by-N matrix A, such that A*diag(D) represents
		     the input matrix.
		     On exit,
		     A_onexit * D_onexit represents the input matrix A*diag(D)
		     post-multiplied by a sequence of Jacobi rotations, where the
		     rotation threshold and the total number of sweeps are given in
		     TOL and NSWEEP, respectively.
		     (See the descriptions of D, TOL and NSWEEP.)

	   LDA

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

	   D

		     D is DOUBLE PRECISION array, dimension (N)
		     The array D accumulates the scaling factors from the fast scaled
		     Jacobi rotations.
		     On entry, A*diag(D) represents the input matrix.
		     On exit, A_onexit*diag(D_onexit) represents the input matrix
		     post-multiplied by a sequence of Jacobi rotations, where the
		     rotation threshold and the total number of sweeps are given in
		     TOL and NSWEEP, respectively.
		     (See the descriptions of A, TOL and NSWEEP.)

	   SVA

		     SVA is DOUBLE PRECISION array, dimension (N)
		     On entry, SVA contains the Euclidean norms of the columns of
		     the matrix A*diag(D).
		     On exit, SVA contains the Euclidean norms of the columns of
		     the matrix onexit*diag(D_onexit).

	   MV

		     MV is INTEGER
		     If JOBV .EQ. 'A', then MV rows of V are post-multipled by a
				      sequence of Jacobi rotations.
		     If JOBV = 'N',   then MV is not referenced.

	   V

		     V is DOUBLE PRECISION array, dimension (LDV,N)
		     If JOBV .EQ. 'V' then N rows of V are post-multipled by a
				      sequence of Jacobi rotations.
		     If JOBV .EQ. 'A' then MV rows of V are post-multipled by a
				      sequence of Jacobi rotations.
		     If JOBV = 'N',   then V is not referenced.

	   LDV

		     LDV is INTEGER
		     The leading dimension of the array V,  LDV >= 1.
		     If JOBV = 'V', LDV .GE. N.
		     If JOBV = 'A', LDV .GE. MV.

	   EPS

		     EPS is DOUBLE PRECISION
		     EPS = DLAMCH('Epsilon')

	   SFMIN

		     SFMIN is DOUBLE PRECISION
		     SFMIN = DLAMCH('Safe Minimum')

	   TOL

		     TOL is DOUBLE PRECISION
		     TOL is the threshold for Jacobi rotations. For a pair
		     A(:,p), A(:,q) of pivot columns, the Jacobi rotation is
		     applied only if DABS(COS(angle(A(:,p),A(:,q)))) .GT. TOL.

	   NSWEEP

		     NSWEEP is INTEGER
		     NSWEEP is the number of sweeps of Jacobi rotations to be
		     performed.

	   WORK

		     WORK is DOUBLE PRECISION array, dimension (LWORK)

	   LWORK

		     LWORK is INTEGER
		     LWORK is the dimension of WORK. LWORK .GE. M.

	   INFO

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

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   September 2012

       Further Details:
	   DGSVJ0 is used just to enable DGESVJ to call a simplified version of itself to work on
	   a submatrix of the original matrix.

       Contributors:
	   Zlatko Drmac (Zagreb, Croatia) and Kresimir Veselic (Hagen, Germany)

       Bugs, Examples and Comments:
	   Please report all bugs and send interesting test examples and comments to
	   drmac@math.hr. Thank you.

       Definition at line 218 of file dgsvj0.f.

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

Version 3.4.2				 Tue Sep 25 2012			      dgsvj0.f(3)
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