.TH "TESTING/EIG/dbdt03.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*-
.ad l
.nh
.SH NAME
TESTING/EIG/dbdt03.f
.SH SYNOPSIS
.br
.PP
.SS "Functions/Subroutines"

.in +1c
.ti -1c
.RI "subroutine \fBdbdt03\fP (uplo, n, kd, d, e, u, ldu, s, vt, ldvt, work, resid)"
.br
.RI "\fBDBDT03\fP "
.in -1c
.SH "Function/Subroutine Documentation"
.PP 
.SS "subroutine dbdt03 (character uplo, integer n, integer kd, double precision, dimension( * ) d, double precision, dimension( * ) e, double precision, dimension( ldu, * ) u, integer ldu, double precision, dimension( * ) s, double precision, dimension( ldvt, * ) vt, integer ldvt, double precision, dimension( * ) work, double precision resid)"

.PP
\fBDBDT03\fP 
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\fBPurpose:\fP
.RS 4

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!>
!> DBDT03 reconstructs a bidiagonal matrix B from its SVD:
!>    S = U' * B * V
!> where U and V are orthogonal matrices and S is diagonal\&.
!>
!> The test ratio to test the singular value decomposition is
!>    RESID = norm( B - U * S * VT ) / ( n * norm(B) * EPS )
!> where VT = V' and EPS is the machine precision\&.
!> 
.fi
.PP
 
.RE
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\fBParameters\fP
.RS 4
\fIUPLO\fP 
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.nf
!>          UPLO is CHARACTER*1
!>          Specifies whether the matrix B is upper or lower bidiagonal\&.
!>          = 'U':  Upper bidiagonal
!>          = 'L':  Lower bidiagonal
!> 
.fi
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.br
\fIN\fP 
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!>          N is INTEGER
!>          The order of the matrix B\&.
!> 
.fi
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\fIKD\fP 
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!>          KD is INTEGER
!>          The bandwidth of the bidiagonal matrix B\&.  If KD = 1, the
!>          matrix B is bidiagonal, and if KD = 0, B is diagonal and E is
!>          not referenced\&.  If KD is greater than 1, it is assumed to be
!>          1, and if KD is less than 0, it is assumed to be 0\&.
!> 
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\fID\fP 
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!>          D is DOUBLE PRECISION array, dimension (N)
!>          The n diagonal elements of the bidiagonal matrix B\&.
!> 
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\fIE\fP 
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!>          E is DOUBLE PRECISION array, dimension (N-1)
!>          The (n-1) superdiagonal elements of the bidiagonal matrix B
!>          if UPLO = 'U', or the (n-1) subdiagonal elements of B if
!>          UPLO = 'L'\&.
!> 
.fi
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\fIU\fP 
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!>          U is DOUBLE PRECISION array, dimension (LDU,N)
!>          The n by n orthogonal matrix U in the reduction B = U'*A*P\&.
!> 
.fi
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\fILDU\fP 
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!>          LDU is INTEGER
!>          The leading dimension of the array U\&.  LDU >= max(1,N)
!> 
.fi
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\fIS\fP 
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!>          S is DOUBLE PRECISION array, dimension (N)
!>          The singular values from the SVD of B, sorted in decreasing
!>          order\&.
!> 
.fi
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.br
\fIVT\fP 
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!>          VT is DOUBLE PRECISION array, dimension (LDVT,N)
!>          The n by n orthogonal matrix V' in the reduction
!>          B = U * S * V'\&.
!> 
.fi
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\fILDVT\fP 
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!>          LDVT is INTEGER
!>          The leading dimension of the array VT\&.
!> 
.fi
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\fIWORK\fP 
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!>          WORK is DOUBLE PRECISION array, dimension (2*N)
!> 
.fi
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.br
\fIRESID\fP 
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.nf
!>          RESID is DOUBLE PRECISION
!>          The test ratio:  norm(B - U * S * V') / ( n * norm(A) * EPS )
!> 
.fi
.PP
 
.RE
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\fBAuthor\fP
.RS 4
Univ\&. of Tennessee 

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Univ\&. of California Berkeley 

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Univ\&. of Colorado Denver 

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NAG Ltd\&. 
.RE
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Definition at line \fB133\fP of file \fBdbdt03\&.f\fP\&.
.SH "Author"
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Generated automatically by Doxygen for LAPACK from the source code\&.