.TH "SRC/cgsvj0.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*-
.ad l
.nh
.SH NAME
SRC/cgsvj0.f
.SH SYNOPSIS
.br
.PP
.SS "Functions/Subroutines"

.in +1c
.ti -1c
.RI "subroutine \fBcgsvj0\fP (jobv, m, n, a, lda, d, sva, mv, v, ldv, eps, sfmin, tol, nsweep, work, lwork, info)"
.br
.RI "\fBCGSVJ0\fP pre-processor for the routine cgesvj\&. "
.in -1c
.SH "Function/Subroutine Documentation"
.PP 
.SS "subroutine cgsvj0 (character*1 jobv, integer m, integer n, complex, dimension( lda, * ) a, integer lda, complex, dimension( n ) d, real, dimension( n ) sva, integer mv, complex, dimension( ldv, * ) v, integer ldv, real eps, real sfmin, real tol, integer nsweep, complex, dimension( lwork ) work, integer lwork, integer info)"

.PP
\fBCGSVJ0\fP pre-processor for the routine cgesvj\&.  
.PP
\fBPurpose:\fP
.RS 4

.PP
.nf
 CGSVJ0 is called from CGESVJ as a pre-processor and that is its main
 purpose\&. It applies Jacobi rotations in the same way as CGESVJ does, but
 it does not check convergence (stopping criterion)\&. Few tuning
 parameters (marked by [TP]) are available for the implementer\&.
.fi
.PP
 
.RE
.PP
\fBParameters\fP
.RS 4
\fIJOBV\fP 
.PP
.nf
          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 postmultiplying the N-by-N array V\&.
                (See the description of V\&.)
          = 'A': the product of the Jacobi rotations is accumulated
                 by postmultiplying the MV-by-N array V\&.
                (See the descriptions of MV and V\&.)
          = 'N': the Jacobi rotations are not accumulated\&.
.fi
.PP
.br
\fIM\fP 
.PP
.nf
          M is INTEGER
          The number of rows of the input matrix A\&.  M >= 0\&.
.fi
.PP
.br
\fIN\fP 
.PP
.nf
          N is INTEGER
          The number of columns of the input matrix A\&.
          M >= N >= 0\&.
.fi
.PP
.br
\fIA\fP 
.PP
.nf
          A is COMPLEX array, dimension (LDA,N)
          On entry, M-by-N matrix A, such that A*diag(D) represents
          the input matrix\&.
          On exit,
          A_onexit * diag(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\&.)
.fi
.PP
.br
\fILDA\fP 
.PP
.nf
          LDA is INTEGER
          The leading dimension of the array A\&.  LDA >= max(1,M)\&.
.fi
.PP
.br
\fID\fP 
.PP
.nf
          D is COMPLEX array, dimension (N)
          The array D accumulates the scaling factors from the complex 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\&.)
.fi
.PP
.br
\fISVA\fP 
.PP
.nf
          SVA is REAL 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 A_onexit*diag(D_onexit)\&.
.fi
.PP
.br
\fIMV\fP 
.PP
.nf
          MV is INTEGER
          If JOBV = 'A', then MV rows of V are post-multiplied by a
                           sequence of Jacobi rotations\&.
          If JOBV = 'N',   then MV is not referenced\&.
.fi
.PP
.br
\fIV\fP 
.PP
.nf
          V is COMPLEX array, dimension (LDV,N)
          If JOBV = 'V' then N rows of V are post-multiplied by a
                           sequence of Jacobi rotations\&.
          If JOBV = 'A' then MV rows of V are post-multiplied by a
                           sequence of Jacobi rotations\&.
          If JOBV = 'N',   then V is not referenced\&.
.fi
.PP
.br
\fILDV\fP 
.PP
.nf
          LDV is INTEGER
          The leading dimension of the array V,  LDV >= 1\&.
          If JOBV = 'V', LDV >= N\&.
          If JOBV = 'A', LDV >= MV\&.
.fi
.PP
.br
\fIEPS\fP 
.PP
.nf
          EPS is REAL
          EPS = SLAMCH('Epsilon')
.fi
.PP
.br
\fISFMIN\fP 
.PP
.nf
          SFMIN is REAL
          SFMIN = SLAMCH('Safe Minimum')
.fi
.PP
.br
\fITOL\fP 
.PP
.nf
          TOL is REAL
          TOL is the threshold for Jacobi rotations\&. For a pair
          A(:,p), A(:,q) of pivot columns, the Jacobi rotation is
          applied only if ABS(COS(angle(A(:,p),A(:,q)))) > TOL\&.
.fi
.PP
.br
\fINSWEEP\fP 
.PP
.nf
          NSWEEP is INTEGER
          NSWEEP is the number of sweeps of Jacobi rotations to be
          performed\&.
.fi
.PP
.br
\fIWORK\fP 
.PP
.nf
          WORK is COMPLEX array, dimension (LWORK)
.fi
.PP
.br
\fILWORK\fP 
.PP
.nf
          LWORK is INTEGER
          LWORK is the dimension of WORK\&. LWORK >= M\&.
.fi
.PP
.br
\fIINFO\fP 
.PP
.nf
          INFO is INTEGER
          = 0:  successful exit\&.
          < 0:  if INFO = -i, then the i-th argument had an illegal value
.fi
.PP
 
.RE
.PP
\fBAuthor\fP
.RS 4
Univ\&. of Tennessee 
.PP
Univ\&. of California Berkeley 
.PP
Univ\&. of Colorado Denver 
.PP
NAG Ltd\&. 
.RE
.PP
\fBFurther Details:\fP
.RS 4
CGSVJ0 is used just to enable CGESVJ to call a simplified version of itself to work on a submatrix of the original matrix\&.
.RE
.PP
\fBContributor:\fP
.RS 4
Zlatko Drmac (Zagreb, Croatia)
.RE
.PP
\fBBugs, Examples and Comments:\fP
.RS 4
Please report all bugs and send interesting test examples and comments to drmac@math.hr\&. Thank you\&. 
.RE
.PP

.PP
Definition at line \fB216\fP of file \fBcgsvj0\&.f\fP\&.
.SH "Author"
.PP 
Generated automatically by Doxygen for LAPACK from the source code\&.