LAPACK
3.4.2
LAPACK: Linear Algebra PACKage

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Functions/Subroutines  
subroutine  dgsvj0 (JOBV, M, N, A, LDA, D, SVA, MV, V, LDV, EPS, SFMIN, TOL, NSWEEP, WORK, LWORK, INFO) 
DGSVJ0 preprocessor for the routine sgesvj. 
subroutine dgsvj0  (  character*1  JOBV, 
integer  M,  
integer  N,  
double precision, dimension( lda, * )  A,  
integer  LDA,  
double precision, dimension( n )  D,  
double precision, dimension( n )  SVA,  
integer  MV,  
double precision, dimension( ldv, * )  V,  
integer  LDV,  
double precision  EPS,  
double precision  SFMIN,  
double precision  TOL,  
integer  NSWEEP,  
double precision, dimension( lwork )  WORK,  
integer  LWORK,  
integer  INFO  
) 
DGSVJ0 preprocessor for the routine sgesvj.
Download DGSVJ0 + dependencies [TGZ] [ZIP] [TXT]DGSVJ0 is called from DGESVJ as a preprocessor 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.
[in]  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 NbyN array V. (See the description of V.) = 'A': the product of the Jacobi rotations is accumulated by postmulyiplying the MVbyN array V. (See the descriptions of MV and V.) = 'N': the Jacobi rotations are not accumulated. 
[in]  M  M is INTEGER The number of rows of the input matrix A. M >= 0. 
[in]  N  N is INTEGER The number of columns of the input matrix A. M >= N >= 0. 
[in,out]  A  A is DOUBLE PRECISION array, dimension (LDA,N) On entry, MbyN matrix A, such that A*diag(D) represents the input matrix. On exit, A_onexit * D_onexit represents the input matrix A*diag(D) postmultiplied 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.) 
[in]  LDA  LDA is INTEGER The leading dimension of the array A. LDA >= max(1,M). 
[in,out]  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 postmultiplied 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.) 
[in,out]  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). 
[in]  MV  MV is INTEGER If JOBV .EQ. 'A', then MV rows of V are postmultipled by a sequence of Jacobi rotations. If JOBV = 'N', then MV is not referenced. 
[in,out]  V  V is DOUBLE PRECISION array, dimension (LDV,N) If JOBV .EQ. 'V' then N rows of V are postmultipled by a sequence of Jacobi rotations. If JOBV .EQ. 'A' then MV rows of V are postmultipled by a sequence of Jacobi rotations. If JOBV = 'N', then V is not referenced. 
[in]  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. 
[in]  EPS  EPS is DOUBLE PRECISION EPS = DLAMCH('Epsilon') 
[in]  SFMIN  SFMIN is DOUBLE PRECISION SFMIN = DLAMCH('Safe Minimum') 
[in]  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. 
[in]  NSWEEP  NSWEEP is INTEGER NSWEEP is the number of sweeps of Jacobi rotations to be performed. 
[out]  WORK  WORK is DOUBLE PRECISION array, dimension (LWORK) 
[in]  LWORK  LWORK is INTEGER LWORK is the dimension of WORK. LWORK .GE. M. 
[out]  INFO  INFO is INTEGER = 0 : successful exit. < 0 : if INFO = i, then the ith argument had an illegal value 
Definition at line 218 of file dgsvj0.f.